The professor is responsible, and he will reply to almost all your emails

Amazing lecture; office hour is really helpful. He made me realize math is COOL!!!

He is so patient that he will answer an easy question for many times. What's more, he makes us find that math is so cool!!!!!

His class is easy to understand. He explains every detail clearly and gives students time to raise their questions. He has a clear structure and the office hour is really helpful. I love his class!!!

John is a nice teacher. He cares about students learning while treating every student fairly in and out of the classroom.

Best TA in the calculus room !

The best Math teacher I have ever met in Davis. If you have a chance to take his class, go for it! You will learn a lot from him. He is very inspirational and gives students interesting problems to solve!

He is a great professor, but his midterms are very difficult.

You gotta do your homework to get good grades on quizzes even though it is not required. The midterm was somewhat hard but his lecture is fun so I recommend him.

His lecture is of so much fun, so make sure you attend each one, even the one before Thanksgiving because he will lecture some more challenging stuff from MAT 21D in small class size. His HW has no solution and no need for submission, ask him on Piazza. 40% of two midterms, 35% of final, 25% of weekly quiz. His midterm 2 was hard with average 56%.

By far, the best math teacher I've ever had, period. His lectures are enjoyable and fun, but also extremely clear so it's easy to understand concepts. He is also super open to answering questions in class, and on piazza. His midterms (especially the second one) are no joke, so please do attend lectures and do ALL the homework and the review sets.

Challenor is probably the best calculus professor on campus. I've heard some iffy things about other professors, but Challenor only has positive feedback. His lectures were extremely helpful and were not boring at all. He overall seems like a cool dude. Also do not skip lectures because the midterms are kinda rough and based heavily on lectures.

Great guy, lectures were always interesting and fun because he is clearly passionate about what he's doing. He teaches very clearly and enthusiastically. Midterms were graded pretty picky, and some questions were challenging. You'll learn a lot in this class.

Professor Challenor is a fantastic teacher. His lectures are interesting and useful and sometimes is hard to believe this is his first year of teaching. The quizzes are very helpful and can help students understand the material better. He responses to every question. His office hour is helpful to study the material. Overall the class is enjoyable.

Very fun lecture with concepts clearly explained, moderate amount of HW with no solution but you can ask on Piazza. Midterm 2 was much more difficult than 1. Final is OK. He will teach MAT 16A for winter quarter, 2020.

John Challenor... my God what a man. But seriously, he loves his job, knows how to teach, and loves his students. Clap every time he does a bad drawing. Or even better, mention integration by parts as ultraviolet voodoo and see his face. Make sure you do homework and go to office hours for a fun time. Do the work and ask questions. He loves to help

Dr. Challenor is a wonderful teacher, I definitely recommend him for math! Not only does he teach things without frills and is very direct, but he is also very helpful and genuinely cares about the students. He is also so pumped about math that it is downright adorable. My most enjoyable class this quarter ^u^

Caring and patient guy with funny lecture. Graded only by weekly quiz, 2 midterms, and a final. Midterm 2 was the hardest. He answered questions within 5 min on Piazza. HWs, even without solution, are of great help to exams. You will love him.

My grade does not reflect on the professor as illness prevented me from doing as well as I could have in the class. Challenor is an amazing math professor, very approachable, funny and inspirational. There are weekly quizzes that count for 20% of the grade, 2 exams and a final.

Professor Challenor was the best professor to have as an incoming freshman student. He grades 25% on weekly quizzes (based on HW and lecture concepts), 2 midterms (20% each), and the final (35%). Second midterm was brutal and did well below average (why I ended with a C). Challenor also responds to every question quickly. Highly Recommend.

Dude he's a real gem. I am now sitting in another math professor's classroom and thinking back to the time when I had Professor Challenor, and oh man they can't compare. Professor Challenor's lectures were extremely helpful and even though we didn't use the textbook I still understood everything perfectly. Gives me passion for studying math too :)

Honestly he really is a "real gem". I didn't expect that teachers would be good at a UC, since there are so many students. But he really does want everyone to succeed. His lectures are interesting and he is always open to answer your questions. His homework has a few challenging questions but it's not too bad. I was always excited to go to math! :)

An amazing guy, genuinely. Makes math so interesting and fun, makes it easy to learn but also challenging. You can just tell he's passionate about what he's doing. I wish I could have him again, other math Profs just do NOT compare. This guy is gonna teach you math, and you're gonna love it. He should definitely be #1 on your preferred prof list.

He's a fun teacher, but the content is hard! Most of the people who did well in his class took ap calc in high school, and without that background, I was at a disadvantage. He skips steps in examples, but if you ask him to clarify he's good at explaining what he's doing. If you take his class, take advantage of tutoring!

Challenor is a great professor, I would highly recommend him. He would actually teach you how to do math!!! I could have gotten a higher grade if I had put in more effort (a.k.a not the professors fault). He is amazing, he made me enjoy calculus. He knows how to teach unlike other UC Davis math professors. I wish he taught MAT 16B next quarer ):

The BEST professor I had at UC Davis. TAKE him, please!!! I didn't like math at all, but his class is wonderful. His homework is not mandatory to do but do it and you will be good at midterms and final.

His lectures are a tad fast and he doesn't necessarily explain every step, but he means well and really wants you to understand. He doesn't post a key for homework which is inconvenient but he responds very quickly on piazza. Overall a good professor.

Wow. Professor Challenor was one of the best professors I've had and the best math teacher I've ever had. Although I didn't excel grade-wise (due to some health issues), he made everything extremely understandable. I've always hated math and this quarter math was my favorite subject. Highly recommend!!

I took Challenor for 21B . His lectures were easy to follow and understand. Before class starts, he asks if anyone has questions. He always likes when you stop him to ask questions. Super nice! During office hours, he is super helpful. He gives good feedback and shows you step by step how to solve problems if you are confused. He is great teacher!

Such a funny dude and a great lecturer. he told me that when I get to upper-division math classes to come to talk to him about the material and believe me I plan on it, such an insightful professor.

Grade math prof. HW is all from the textbook and easy. I barely show up to lectures but I can ace all the HWs and MTs simply from reading the textbook

I'm so glad I took Professor Challenor, I learned so much from him through this difficult online quarter. He teaches the material clearly and makes it easy to understand. He gives super reasonable Midterms that are just like the Homework problems he assigns. Definitely take a class with him if you can

The three midterms we had were pretty easy since they were exactly like the homework (so as long as you redo the hw and understand it, you should be fine). The final was harder than the midterms though.

The material in this class is much more difficult than the calculus series so previewing the topics before lecture helps. Office hours and Piazza help a lot for the homework, so use your resources. He's such a nerd for math and will go above and beyond to help students understand the material. Final really tested your knowledge but was doable.

The material in MAT108 is so cool and John did a great job presenting alll the cool stuff. Plus the rants on textbook and terrible math jokes, this class is definitely my favorite math class! John really really cares about his students and genuinely want us to succeed. 100% recommend!!!

Very responsive to questions both in lecture and on Piazza. I've had professors who answer questions in a condescending way so I've been scared, but John's chill and supportive! HW forces you to think about definitions and what follows in order to write a coherent proof. Really wish there was a physics professor like him :(

John is an awesome professor. He doesn't like pre-calc because he says he doesn't get to show us the fun stuff but he still does a great job of teaching it. As long as you watch the lectures and do the homework his class will be a breeze.

I failed precalc twice, then passed calculus with Challenor. Great professor. Very clear and easy to listen to. Seems to really enjoy his job and portrays the concepts that he teaches well. If you have the chance to take math with Challenor, do it. It was one of my best experiences with this class.

John is hands down the best in the math Department. He is very nice and cares about his students. His office hours are a life saver and his lectures are fun to attend. Tests are fairly easy. Might be a tough class if you have no calc background but definitely doable. He replied very quickly. Quizzes are straight out of the optional HW.

John is an amazing teacher & he cares for his students. He always goes back to previous slides or answers questions in the middle of a lecture if students ask. I would highly recommend going to OH and doing all (optional) HW. His midterms are pretty easy, and he gives partial points. His final was a bit harder, but the TA graded very lightly.

John was a great teacher and you can tell he is passionate about what he is teaching. The class was based on four tests and a final, but all of the questions were fair and based exactly on the homework. John made learning math so much more pleasant and was very caring towards students' situations in the pandemic. Overall a great guy and teacher!

John was really helpful especially during this covid pandemic. I was really struggling in his class since I was at a disadvantage for not taking AP Calculus in high school. By studying extra hard for his exams, I was able to end the quarter with a B. Advice for future students: email him to see what are the best ways to study for his exams!!

John is an amazing professor! Even though I already took calc in HS, his lectures were so enjoyable and you could really see his passion for math. Hes a genuinely great guy and I couldnt recommend his class enough. Quiz every week directly from HW, three midterms of average difficulty, and one final which was on the difficult side, but ok!

john is such an amazing and personable prof! his lectures were so engaging (even at 9am) & he has a genuine passion for math. grading was very fair. quizzes & midterms were similar to hw problems. final was a bit tougher but doable. office hrs were very helpful, and he always made me excited to learn. really wished i could've met him in person.

He responds so fast and is super nice. Like you can ask the dumbest questions and hell answer them nicely, which I know other profs wont do. Just take him you wont regret it!!

He's a good professor overall. I took him online so I can't compare him with in-person lectures however he is pretty good at what he does. I can tell he is passionate and he is very generous when it comes to helping and trying to understand math. Office hours are pretty helpful and his tests aren't that bad even though your grade is based on tests.

Great professor! Professor John was very enthusiastic about teaching math and it really showed. Explained problems and concepts well. Optional homework but highly recommended to do if you want to pass the class. Exam every 2 weeks, pretty straight forward. Final was a little tricky but manageable!

The best lecturer in the math department. If you have the chance to take his class, do it. He explains all the concepts and goes through the proofs really well so everyone can understand. I love him. I wish he could teach all of my math classes. The tests are hard, but he prepares you. He is so inspiring and his lectures made me excited about math.

One of the best professors I've had so far. He is very passionate about teaching and wants his students to succeed. Grades were based on weekly quizzes, 3 midterms, and a final. His exams are tough, but doing the optional HW and review problems are helpful. His office hours are also super helpful for questions!

Professor Challenor really cares about his students and will take more effort to help them. He has good lectures. He doesnt give answers to the hw which is kind of annoying. His tests are pretty fair if you study but his final is hard.

One of my fave math professors. He makes calc digestible, but will sometimes skip calculations but you're always open to ask questions. Quizzes are from the "optional" homework which was usually "fun". Definitely go to OH to solve the more difficult ones. His tests aren't ridiculously hard but they're a mix of doable and reasonably difficult.

While this class was a bit difficult, the lectures were really clear and interesting. We're only graded on assessments, but the homework prepares you well for them. He's also very willing to answer questions and is very enthusiastic about the class. Overall a great experience.

Very enthusiastic about teaching math and carried throughout his lectures. Homework was optional, but you should keep up with it for extra practice. It was a bit annoying to have no answer key for the homework, although he is very helpful during office hours. His exams were very tricky; make sure to be well prepared.

He is really a nice instructor. He is very passionate and his lectures are very clear and he's ready to answer all the questions from the students. The homework outside the class is optional, but the problems in quizzes are taken from the homework. The midterm and final are not very difficult, and he gives bonus questions in those exams.

He is the best professor ever, he's so caring and knows how to teach for sure.

Challenor is by far the best math professor I've had at UC Davis. His exams are super fair as long as you do the hw. He tells you how to study for them and follows his own criteria. He explains really well, good lecturer, and great examples. I wish I would've had him for other classes. If you can take him, do it!

Professor Challenor was by far the best math professor I have had a UC Davis and was an amazing way to finish the MAT series. His tests are very fair and just do the hw and you will succeed. Awesome dude and cares about his students.

I gave 4/5 but I would give 3.5/5 if decimals were allowed. I personally took the class P/NP so I was a bit surprised to get an A-. Decent curve, 84 above is A-. Class is pretty easy and this professor gives you a solid foundation, the only thing I didn't like was how there were no solutions to the quizzes posted and grading was slow.

Best lecturer I have had so far. Enough said.

He is very humorous and I enjoyed his lectures

"The fundamental theorem of calculus was only the beginning."

Amazing lecturer, favorite professor I've had so far! The pace of the class is fairly easy to keep up with and the weekly quizzes helped me stay on top. HW is optional but highly recommend you do them if you want to get A's on all your quizzes. Tests are pretty fair imo and he curves your grade at the end of the quarter! Take his class!!

Best calc professor I've ever had. As long as you do the homework and listen in on office hours the quizzes are a breeze- just 2 Q's. The midterms can be challenging though. Just practice- he's very clear with his words and what he expects and has a great understanding /passion for the material that he makes jokes. Best Calc Professor ever.

Challenor is a decent professor. His homework is hard and without a solution, but we have to do it right to do good on quizzes. Exams are hard especially the first one. The final grade is determined by exams and quizzes with no credit for homework. His lectures are awesome and office hour helps a lot. Hard course but decent choice.

This was probably the toughest math class I've ever taken, but prof Challenor really went above and beyond to make sure everyone understood the lectures. You only get out what you put into this class, though, so even though homework may not be 'required' you definitely need to do it. Office hours were also really helpful

The BEST instructor I've ever met. You will learn a lot from him since he is a true teacher.

He is an amazing professor. The only downside is that he doesnt give hw solutions, but as long as you have a study group you should be fine. 21D is a really hard class in general, so you have to study really hard to do well. Overall, the exams were on the harder end, but the quizzes were very straightforward.

Professor Challenor is great at teaching and you can tell he has a passion for math. His lectures were easy to follow and he was always eager to answer questions. He also went over homework problems at the beginning of class to help with understanding. The only downside to the class is that there are quizzes every week. (Two quizzes get dropped)

This professor is amazing. The quizzes every week (2 dropped) are pretty easy, just make sure to do the hw. When studying for the midterms, don't cram last minute . Study a bit every day for a week and you'll be fine. Utilize his office hours because they are really helpful. Find a study group because it really helps, & do lots of practice problems

i absolutely loved challenor. he is super comfortable taking extra time to answer/repeat questions people have & has very organized lectures. very clear grading format (weekly quizzes that are not bad at all), 2 midterms, 1 final. super funny/easy going. cares about every single student too which is rare. if i could take every class w him i would.

Good guy, tough class, made it bearable. graded based on 9 quizzes, 2 dropped, 2 midterms & a final. HW was optional but helpful for quizzes.

Challenor good professor. There's homework assigned after every lecture but they are not graded nor collected. There is one quiz based on the homework every week. Challenor does not give out solutions to the HW (it's not that bad, be active on discord and use online calcs/go to OH etc). DO THE HOMEWORK. DONT fall behind! also avoid Thomas lmao.

You will do great in this class if you use your resources wisely. Using platforms like discord and campus wire really helps with HW. He does not release HW solutions so that's a downside but if you collaborate on discord, you will be fine. Quiz and Midterm heavy, there's HW but not graded. Overall will take again but you gotta work for your grade.

Explains the concepts really well and in a straightforward manner! There are weekly quizzes that are based on the previous week's hw. There is hw after each lecture, but they're ungraded, and he doesn't post solutions but will go over them during OH if requested. He records the lectures but usually not the OH. Overall, a great choice!

Professor Challenor is a nice great proessor. You will learn a lot in his class and MAT 21D is very important for many other calsses. Choosing him as professor for this course is a wise choice.

One of the best math Professors I’ve ever had. I was worried about hearing that HW answers aren’t posted, but if you’re lost he guides you on how to do them on Campuswire. Exams are moderately hard, but as long as you do the HW and the MT/Final Reviews it won’t be super difficult. He is very caring and engages well with students!

Such an amazing professor! He is an enthusiastic lecturer who constantly makes sure the students understand the content. Weekly quizzes, but if you attend OH and do the homework it's not bad at all. His exams also aren't too hard if you keep up with the homework, and he is always available to answer questions. Would 100% take him again.

Lectures were very organized and easy to understand. Does not hesitate to answer your questions during lectures and will go over confusing parts as many times as needed. Always eager to help outside of class. Only downside is no solutions to homework and quizzes, but if you ask lots of questions, it shouldn't be a problem.

Understand the hw and you can do well. Hw is not too bad, but youre not given answers so being in a group discord is ideal.

There are no solutions to the HW, he encourages you to work with other students and go to office hours to ask questions. Weekly quizzes, two are dropped, 2 midterms and a final, so test heavy but fair questions. Amazing teacher, he cares very much and he's able to explain concepts well.

def go to office hrs. do all the optional hw. just be clear on everything. and try not to make silly mistakes on tests and you're all good.

Overall, very good teacher that cares about the material and his students. Homework is optional, but is practically required if you want to get a good grade. Unfortunately no answer keys for the HW, but you can easily receive help in his office hours or through the discord. Exams are tough but not impossible. DO THE HOMEWORK.

Best math professor at Davis. Very clear in lectures and I found this class to be easier than 17A. Would always pause class to make sure everyone understood the material. Only downside is that there is no homework solutions making it hard to understand material if you can't go to office hours. Make sure you know this before picking him

Clear and concise teaching style. Will go fast some times during lecture if running into technological difficulties but makes sure to catch you up by posting additional videos relating to the same day's lecture online. Content is easy to understand if you do the homework, which greatly help you on weekly quizzes. Midterms and Finals are fair.

AMAZING PROFESSOR! Very caring and explains everything well. He does not give homework answers though.

He is a very caring and passionate professor, and explains stuff well in lectures. His homework was very helpful for exams despite it being "optional." As long as you make sure you understand and can do the HW you should do fine. My only complaint is that grading is tough on exams, do not rely on getting partial credit.

I found that Professor Challenor had great lectures, that were both interesting and engaging and very thorough, and was very receptive to questions and feedback in response to emails and in office hours.

Great lecturer and explains everything super clearly. Doesn't post answers to the homework but uses campuswire to answer any questions which is really helpful. Tests are not too hard and he sometimes even throws in hints for some of the questions. Seems like he actually cares about his students and is enthusiastic about math.

Professor Challenor gives a really clear lecture and he explains very well. The optional HW in every lecture is sometimes challenging, but it helps a lot for weekly quizzes, and to prepare for the midterm. Although there is no solutions, the office hours are really helpful and he always put effort in explaining every doubts the students have.

Dr. Challenor is one of the best professors you'll meet! Amazing class, very straightforward material (a little too straightforward), very respectful, just an awesome guy. Would take him again if I could. Beware, he does not give A+; the highest you can get is an A!

Best professor in the MAT 17 series. The grade distribution is a little harsh, in that your grade is based entirely on quizzes and exams. It was evident that he truly loves math, which made the class both fun and engaging. He always asked if we had any questions and responded quickly to concerns on Campuswire. Exams were fair. Phenomenal lecturer!

Challenor is an amazing lecturer and is open to clarify any confusion during class.The grading and partial credit can be pretty tough on the exams unless you get really close to the answer, but as long as you do the homework and ask questions during office hours, you'll be just fine for the quizzes and exams.

Challenor is a great professor. His lectures are extremely clear and his is more than willing to clarify confusing topics and take the extra time to clear up any confusion. The main issue I had with his class is that the grade was based on weekly quizzes and three exams alone. Homework was assigned for practice but no keys were ever provided.

Best professor I've had. Easy to understand and has very helpful office hours. Tests are very straightforward and are sometimes easier than the homework he gives. Everything is fair. 10/10 would strongly recommend. Plus he curves.

I don't like math. BUT Dr. Challenor made me actually enjoy math a bit!! Lectures went by so fast which means he's so good at engaging his students. I loved his lecturing style! He's great at walking students through questions, especially ppl who struggle. Yes, he doesn't give out HW answers but trust, discord got ya! BEST MATH PROF. Yes yes yes

This class was taught very well, but the test difficulty was very random. there were 4 midterms, I studied the same for all 4 yet, on 2 I averaged a %94 and on the other 2 I averaged a %60, so I never really knew what to expect from the exams, some were easy and some were unnecessarily hard.

The only negative is he does not post homework answers.But there is campuswire which you can use to ask about hw.I watched all the lectures and did hw the night before the midterms, studied till 3/4 am the nights before.The hw is fs harder than the midterm questions and the grading is in a format that is aimed to give you the most points possible.

Challenor clearly has a deep love for math as well as teaching it. He is happy to answer questions during lecture and has a very positive attitude. I don't like math, but Challenor made me actually want to go to class. He was extremely organized and his lectures were easy to follow. Mat21D is a hard class, but i can't recommend Challenor more.

He will be the best option to take MAT 21D with.

Challenor is the best math professor I've had so far in lower-division math, his lectures are really helpful. He is reachable most of the time outside of class, and always likes questions. For those of us that are math majors, he knows a little bit about the upper-division classes, and I would highly recommend him whenever he teaches them.

Everything is good for him. BUT HE DOES NOT GIVE A+ GRADE EVEN IF YOU GOT ALL FULL SCORE IN EXAMS AND QUIZZES!!!

Challenor is amazing and passionate. Holds 4 office hours a week + 1 office hour of his TA's. Responds to emails and Campuswire questions. The material is challenging but I go to almost all office hours where he and his TA explain patiently, and so I do well in the class. Quiz every week but usually simple questions that check for understanding.

I really enjoyed this class and I would love to take more math classes taught by Professor Challenor. If you have to take any math class, he would be the best person to teach it.

Great professor, his lectures and office hours were very helpful if you didn't understand the material covered during the lecture. He is very easy to contact outside of class through campuswire, would definitely recommend taking any class that he is teaching!

That is where I fall in love with maths. Easy to reach out, explain everything crystal clear, very professional. I would major in maths if he can be my prof forever. If you cram before the exam and you screwed up, don't blame the instructor. Blame your own laziness. If you don't want to learn something in college, don't waste your parents' money.

He is accessible, reasonable, and very helpful. Use his office hours as a resource as well as Campuswire for questions. Tests are based on the homework, which there's no answer key for which is what makes office hours so valuable. The weekly quizzes are straight forward. The bottom two grades are dropped from the quizzes. 2 midterms and a final.

Professor Challenor did a great job with 21B. His lectures were good; I'd already taken calculus in high school but there were some things he explained better than my high school teacher. Grading is based on weekly quizzes as well as midterms and a final.

Absolutely amazing professor, weekly quizzes are the only downside I could think of but they're usually just 1-2 questions at most. Grading is fair, lectures were optional to attend, discussion sections were great. Always available for office hours, and homework for 21M specifically was also optional.

His timing during lectures and his organization is amazing. He recorded all his lectures so that we can rewatch them. He is also very easy going and helpful. This professor really knows how to teach. :D 10/10 will take his class again.

Professor Challenor is amazing. He is my first professor here at UC Davis. I took his 21M class. He sets the bar of a good professor so high that all the professors afterwards are less in comparison. If you do the homework and understand the ideas intuitively, and know how to apply them in a creative way, you will do well on the exam.

40% Test in the second week; not easy but curved. Homework is not graded, but similar problems will appear on the quiz 10%, drop lowest two. Final and midterms are hard but similar to homework. It has an overall curve.

Love this prof. He is so patient and explains every question carefully. He records every lecture and office hour. Homework contains very helpful questions. Study guides are provided before midterm and final. Definitely would take his class again. Favorite prof.

Best explanation of mathematical concepts and their application that I've ever had from any professor.

FANTASTIC lecturer. He explains everything in an incredibly clear way and wants to make sure everyone understands. He responds to questions outside class within literal seconds & is incredibly accessible outside of class if you have any questions/concerns. Lectures are streamed on Zoom/recorded. He makes learning calculus less painful :)

I'm taking Math just as a requirement but he is an amazing teacher. Don't think, just take him.

Professor Challenor IS AMAZING! He is very knowledgable about what he is teaching and explains in detail both in lectures and office hours. He is very calm whenever we don't understand a question and will happily guide us to the correct answer. I really like how he is very responsive on Campuswire and how he records his OH the day before midterms.

TAKE THIS PROFESSOR! He is one of the best professors I have learned with. You won't regret!

Respectable guy. Explains concepts really well, made calculus pretty straight-forward. Room for improvement but overall a good experience as far as a calc class goes.

Challenor is a great teacher and explains stuff very clearly. Tests could be challenging but if you do the homework they weren't bad. There were weekly quizzes which could be annoying but were also helpful check-ins to make sure content was understood. Attend lectures and do the homework and you'll do well.

Professor Challenor is the best math professor I've had. He explains concepts very well and provides many examples. Go to office hours whenever you don't understand something. There are 4 half-midterms, 30 minutes each every other week. They are easy if you do the lecture homework (which is optional).

The best mat16b professor. Curved a lot at the end and had the most partial credit.

Best math teacher ever, he is so clear and always asks if we have questions. His exams/quizzes are EXACTLY like the homework and he always had review before exams. One of the best profs I have had, only downside is that he doesnt post homework answers, but you can just use symbolab to look them up so it doesnt really matter. Overall he is the BEST!

Challenor is the best math teacher I've had. He explains concepts very clearly and always answers questions. We had weekly quizzes in discussion, but I always found them pretty easy and they were a good cushion for grading. He has extra office hours before tests, and homework and midterm practices were always super helpful.

Just in the first week of his real analysis course but wow -- he explains things and teaches extremely well which is quite rare. He also records and post notes which is +100 pts. Also his final exam is a oral exam which I love. He's VERY accessible outside of class.

Professor Challenor is awesome! Made a scary class such as Real Analysis much easier to understand and approach. Super accessible and helpful during office hours. Does an oral final exam (only for summer session I think) which seemed odd at first, but he gives you a chance to correct any mistakes during and guides you back if you go off track.

Out of all the Calc profs I've taken at Davis, Challenor was the best. His lectures were very helpful, and his tests were hard but fair. If you want to pass you'll have to take advantage of outside resources, lectures alone weren't enough for me.

Agreed to giving me a recommendation letter in a min after i sent him the email, hes the best, take him.

Challenor is a really good educator, explaining all the concepts in clear and precise steps that allows you to understand the materials easily. Test scores relies on you doing all of the homework(not graded) and engaging in discussion sections on material you're unsure of. All around great professor, definitely take him if you have to take math

Doctor Challenor is a great Professor. I will say one thing though, sometimes his lectures can be confusing. I can't read his handwriting sometimes, but overall MAT21A is an easy class and I took Calculus previously. Make sure you do your homework. He is very forgiving with quizzes. Overall 9/10!

challenor was amazing. he is very clear in his lectures. if you are struggling, his office hours are super helpful, and they're are also drop-in tutoring.12-minute quiz once a week in discussion, and they are very easy. grade two midterms, nine quizzes, and ten worksheets (worksheets graded on completion). he drops the two lowest quizzes, as well.

Super caring, great at explaining math concepts. Weekly quizzes/worksheets to keep you on track. Amazing prof.

As someone who's bad at math Professor Challenor made calc understandable. Attend office hours he goes over the homework, gives answers and sometimes hints to what will be on the quizzes! Weekly quiz is a significant part of overall grade they show what he expects you to know. Do the homework it has no answer key or grade but it will prepare you!

Professor Challenor was good. There are quizzes every week during the discussion sections based on the previous week's homework. The exams weren't bad. STUDY and you'll be fine.

i love this man. i took calc ab & bc in hs and this man is wayyy better at explaining concepts than my hs teacher. he gives many examples in lecture and is quick to respond on campuswire which is a super helpful resource. hosts many office hours and genuinely wants his students to understand calc. he's also hella funny.

Amazing professor very easy to get a B. All hw is optional so 2 midterms and final make up basically the entire grade. Only reason I got a C was because I spent all my time studying for chem instead of calc. Extremely passionate, knowledgeable, and friendly.

He is a super easy grader, I thought I was gonna screw up the final and he saved me. He gave clear lecture, office hour very helpful.

Professor Challenor is super optimistic and knowledgeable about what he teaches; attending his lectures is worthwhile, but does record/lectures through Zoom if you choose not to go. While tests can be on the trickier side, midterm review sheets can prepare you enough. Very accessible through CampusWire, homework is optional/serves as practice.

Very caring and crazy fast responder through email or campus wire. This class is test-heavy with 95% of your grade being weekly quizzes, midterms, and finals. The weekly quizzes are easy and your 2 lowest scores are dropped. If you took calculus before, this class shouldn't be difficult. He is SUPER passionate about math. Go to office hours.

lectures can be on zoom + tests/quizzes make up 95% of your grade + weekly quizzes (can be easy or challenging), excellent lecturer but sometimes can go off tangent +homework is thought-provoking, attempt them, do the practice exams and you'll do great.

Challenor has a reasonable workload: 8 quizzes (2-3 easy ?'s), weekly WS (done in groups), optional HW after lecture, & 3 midterms. Lectures were engaging & he uses lots of visual examples w/ graphs. I struggle with algebra, but he made everything simple. I do wish he posted answers to his HW and MT review, but he records office hours before exams.

homework is optional but much more difficult than tests or quizzes. extremely passionate about math. you'll do good if you take his homework seriously and his notes during lecture are suuuuuuuuper helpful. he teaches in detail which in times can be confusing but overall a good thing, I appreciate him as a professor. i'd take him over anybody else

Dr. Challenor genuinely loves teaching math. He lectures with enthusiasm and is prepared with the lecture material. He is also accessible after class to answer any questions. The quizzes, midterms, and finals were not too difficult either. Do each of the homework he posts after lecture and practice exams and you will get a B at the lowest.

I struggled in this class because his tests are no laughing matter-- the man loves his trig. Yet I did enjoy his lectures and found his enthusiasm for math enjoyable. Do not expect an easy A but I would take Challenor if you're looking for a fair chance at getting an A (better chance than other calc profs)

Challenor was a excellent professor for calc, very straightforward and direct. He LOVES math and is very passionate about what he does. The content is not difficult if you put in the work to study and review. Exams were straightforward. DO THE HOMEWORK! If you do the homework and understand all of the questions you will do well.

Very tough but rewarding teacher, holds great midterm and final reviews and is usually available and super helpful on Campuswire. If you put in the work you can definitely get an A

professor challenor clearly knows math very well, good lecturer but the HWs (that we don't have to turn) could be a bit easier imo

very passionate about what he does, very clear in lecture, i personally had trouble because the examples he would give in lecture were way easier than the midterms, but if you do the homework you should be fine. he makes me wanna like math tho, love him fr

Challenor is the most passionate math prof i've ever had. Not only is he very knowledgeable in his field, but he loves to teach and it shows. He would often crack jokes in class or poke fun at people and it was overall a great time. I hate math, but he makes me want to like it and that's how you know he's awesome at his job.

So glad I waited a quarter to take his class. Lectures are very informative and prepare you well for the weekly quizzes (no graded hw). Exams are hard but fair and graded leniently with lots of partial credit. 21D is known to be very difficult but taking it with Challenor makes it so much less stressful and more enjoyable. He is a legend.

As someone who struggles with math, Challenor is very inspiring. Super accessible and friendly. Curve isn't really great because he's a good professor so a lot of people score well. Make sure to go to office hours and do your homework because it's very similar to the tests.

Good professor, tough class. Optional HW but quizzes similar to HW in discussion every week (lowest 2 dropped) with 2 midterms and a final. Tests have good partial credit opportunities but the curve is small. My only gripe is that he doesn't post the HW solutions or put formulas on the tests. Only take if you need 21D as a prereq, otherwise don't.

Can't imagine anyone else teaching this class better esp over summer session with dense ~2hr lectures MTWF. Impressive that he was able to keep the class engaged given the pace. MT (30% of grade), Final (40%); had ~50% class averages w/big STD. A lot of hard HW (30%) done in latex & graded harshly. Nice Curve but don't expect an A. Lecture recorded

You can tell he loves what he teaches, and that passion bleeds over into his lectures, making what I usually find boring, actually engaging. He grades extremely harshly, but is very reachable outside of class, responding to DMs on Campuswire in mere minutes, even on the weekends. He is extremely accommodating and always listens to student concerns

Clear (and recorded) lectures, does not post lecture notes or slides. Very passionate about material which makes lectures engaging. Readily accessible and answers within hours on campus wire. Tests are fair and like homework problems. There were weekly quizzes in discussion sections (very manageable if hw was done) instead of having to submit hw.

Challenor is a passionate math professor who makes the subject engaging. While the exams can be challenging, doing the homework and attending office hours can help you succeed. I found unstuck ai a useful tool alongside other study resources.

The Professor is very nice! Take his classes!

A great professor! I loved him. His lectures were pretty easy to follow and aren't mandatory but they're not posted online. He's also open to students asking questions during or after class. He's really easy to get ahold of and answers questions relatively quickly. He assigns a lot of homework though and has 3 midterms plus a final.

Amazing professor, check out his office hours!

great prof, really good engaging lectures and super duper helpful in OH, try and go to OH if you're confused about anything at all or just sit in there and listen, weekly quizzes in discussion and no credit for hw so pretty test heavy but if you study you'll generally do well, had an A for most of the class just bombed the final cuz i didnt study

This was the best math professor I've had! he is funny and explains the concepts very well. I recommend going to his office hours and every lecture because it makes it easier to understand because he goes step by step. Also he curves it pretty well! (The weekly quizzes helps a lot on the midterms (final is hard tho))

My 2nd time taking him, I waited for him to teach 17b after 17a since I liked his lectures so much. Engaging lectures, clear explanations, recorded lectures, weekly quizzes, ~3 HWs per week on Webworks, recorded OH before exams, extremely accessible and eager to answer ?'s. His only downside is that he loves trig, and his exams are very hard.

Professor was a good dude but his class is hard for no reason. He has weekly quizzes which are a pain. (He says two drops but if you mess up a small sign or anything you get marked down a bit). Quizzes are also a few questions so if you mess up your grade drops as there are few assignments. Tests are very difficult as well and his curve isn't kind.

I'll be quick: Attend OH (create study group), skip * questions if you're struggling, rewatch recorded lectures, use campuswire & go to TA OH (depends on TA) (+I never took AP calc & was lowkey rlly hard). Drops the 2 lowest Quizzes (9): 25%, MT (2): 40%, Final: 35%. Curved & replaced lowest score from 1 MT's (2) w/higher final score this quarter).

bombed the first two midterms but did ok on the final and managed to pass with barely studying. definitely possible to get an a if you just study a bit

He's really enthusiastic in lectures and is passionate about teaching which makes the class engaging. Helpful in his office hours and responds quickly to Campuswire questions. Lots of Webwork homework's but they do serve as good practice. Midterms are hard but if you do the Canvas homework problems it's fine and final is similar to the Midterms.

Lectures are very clear and he's approachable for questions. His office hours are so helpful and he's a fair grader. Overall I love this professor.

Professor Challenor lectures really well and really cares about all his students. He makes himself accessible to students very frequently and would always go over the allotted time for OH. He is a very difficult professor so I wouldn't recommend taking him if you are not planning on studying. Not a great curve but an amazing professor.

You're doing yourself a disservice if you don't attend Challenor's lectures. He is a 🐐. The class grade was composed of weekly quizzes, two midterms, and the final. Homework is optional, but if you don't do it, you're cooked. Generous curve at the end of the quarter; my friend managed to pass with a 60%.

Excellent prof. Clear lectures. Exams are fair with generous curves. If you can choose him, don't hesitate！

Despite not doing well (given my math experience, I should not have taken this class), I liked it. He's pretty funny, and I had a good TA. It's really impressive how he apparently projects his voice without using a microphone. I don't think I can handle having no mandatory homework, but it's probably a plus for a lot of people!

Quite literally the BEST professor I've had at UCD for a STEM class. Took this class over the summer, and it was graded on two mts, 11-ish hws, and a final. He's super accessible outside of class (Campuswire), easy to follow in lectures, and very passionate abt math, which makes class entertaining. His exams and HWs are tough, but not impossible.

I took Dr. Challenor last quarter and he was the best calc prof I ever had! He was always willing to help during his OH and he loved going on about his fave math topics in class and cracked jokes. He was very passionate about his teaching & that is honestly what kept me engaged throughout the quarter!

Overall great professor. If you're willing to dedicate the time to study you'll do great.

Highly recommend Challenor for 21a. Not many moving parts, was clear what you needed to study, which I love. Pretty hard class though, you need to know things in depth (a lot more intense than 21b in my experience). It's really meant to shape you up for the rest of the 21 series. Challenor was awesome though. I learned a lot.

Really good professor, grade is due to personal skill issues and the fact that I despised calculus. If you have the opportunity, go to lectures and OH, it helped me in actually getting the material. Really understanding, may make concepts harder than presented, but gives good tips on memorizing. Probably one of the best math professors at UC Davis.

Very good at explaining things, posted lecture recordings but not pdfs of notes, be sure to do the ungraded homework. 10/10

Fantastic teacher, knowledgeable, open to questions, and style of building on previous concepts really helps. Be warned, midterms are hard and rigorous but questions can have partial credit. Be sure to do the extra non-graded homework

He was a great professor who really lived by the "no stupid questions" rule. There isn't necessarily a "curve" but if you do better on the final than what you did on one midterm, it replaces that score. The lectures are recorded too and also on zoom if necessary, which is a huge plus when it rains. Awesome and super chill guy, would take again!

One of my favorite professors so far, I wish I could have him for all of the MAT 21 series. He is so passionate about what he does, and he is very kind and understanding and loves any and all questions. Responds to emails and campuswire within a single day. If you have the chance to take him, DO IT! There are few math profs who'll be this great

Professor Challenor is an easy to understand professor during lectures. Provides useful resources to pass. However, at times I DONT believe he went into enough detail during lectures where you could apply the material into the homework assignments. My only other complaint is the final exam! Very hard as the study guide DID NOT help in preparing!

Prof. Challenor's class was very well organized and he's very caring and always stops for questions. He's very clear on his grading and everything else about the class. The final was rough but not impossible but he curves the class so it really wasn't that bad. Overall I liked his class even though I hate math classes.

Dr.Challenor is a professor who takes the time to make sure his students understand what he is teaching. This is one of his strengths. That being said, maybe the material in the HW isn't all taught during lecture but you could try putting two and two together and it usually makes sense. I agree that the final was super hard.

We had 3 midterms worth 20 percent each and the final was 30%, the homework was slightly helpful for practice Before each midterm, we would have a study guide worksheet + office hours, you can get a solid B with that alone but studying more would help a lot. Challenor is very caring and his OHs are easy to understand. Plus the curve was good.

Professor Challenor is great. I was actually signed up to take 150A in the Fall with a different prof and ended up dropping because I was so lost. The stark difference between Challenor and my old prof was wild. He is enthusiastic, lectures clearly, and facilitates great collaboration. Weekly homeworks, 1 midterm, 1 final, very fair grading.

Prof Challenor was awesome! He was very enthusiastic about the material and cared that his students learned the material. Class had 3 midterms (20% each) and a final (30%). The final score replaced any lower midterm scores. The final was very difficult, however he curved the final grades to fairly accommodate. 100% recommend taking his class.

He's fantastic at teaching. Very passionate about calculus and gives plenty of time for questions!!

The prof makes it very easy to pass the class, I did little to no studying. Explains concepts really well in lecture, but the key to passing exams is practicing with homework. I also took a helpful discussion course alongside this class that gave us weekly worksheets on the material. He drops your lowest midterm grade if you do better on the final.

Professor Challenor is a great lecturer and does a great job teaching this class but I think the exams are a little too challenging for students. The homework is helpful for exams and quizzes but there are certain problems on the exam that I feel are too conceptual for a 50 min midterm. Quizzes aren't too difficult as long as you do them!!

Easy to pass, hard to get an A (like many stem courses). Exam questions are similar to the practice midterms, as long as you understand hw and practice midterm (and do outside studying!), you will do fine. Accessible outside class and genuinely wants you to succeed. Cannot say anything about the final yet, but he does make the final more difficult.

There was 3 midterms each worth 20% of grade. If you did better on the final than a midterm, he would replace your midterm grade with your final grade. Gives homework for each lecture. Sign up for Co-class it helps.He gave study guides before exams and held extra office hours that he recorded. If you watched that and do study guide you'll do great!

I love this man. He is so far the only good professor I've had at UC Davis. Not only are his lectures great, but he has more than ample office hours every single day for several hours a day. He even stays after his office hours if people still have questions and it is obvious he is truly passionate about teaching and cares unlike most professors.

He's a really great guy, but I cried more in this class than watching Cyberpunk Edgerunners for the first time.

Dare I say the best professor at Davis. Class is definitely difficult, but that's mainly because of the material. There's also an expectation to have firm conceptual understanding of concepts. If you're complaining about Challenor's midterms and him being a bad prof, actually attend his lectures and go to OH lol

Greatest calc professor oat

1st half of the class is the most difficult but his lectures were great so I had a decent grasp of everything. Really appreciate his enthusiasm through each concept! Don't take HW as optional bc quizzes were HEAVILY based on that week's HW. Redo ALL HW sets related to exam. Heavy workload but minuscule compared to the monster that is PHY9 🥀

I definitely learn something (not telling you) from Prof. Challenor even though my grade was a little below my expectation. I enjoyed those 9 weeks of 21d despite remembering spending more time than most of my classmates on almost all of the hws. A single problem can often take me roughly 2 to 3 hours.

Very caring and considerate, never makes you feel bad for asking questions or needing a refresher on certain topics. If ur struggling or need 1-on-1 help, GO TO OH. Very laid back and you can work on ur hw in there and ask him if you have questions. Exams a bit on difficult side but fair. Quizzes on the simplest questions and act as grade booster.

The quizzes aren't difficult if you do the hw. Good lectures, clearly is passionate about the topic. He really cares about his students and wants them to do well. The exams are difficult but not impossible, go over the hw, reviews and lectures examples! The campus wire is helpful and he is very very good about answering questions on there and in OH

Professor Challenor is an excellent, excellent lecturer I must say. Clarify everything single concept to the root. Make sure you can do HW right after lecture to practice without any confusion. Offer a lot of support outside classes. The only thing is the exam is moderate to hard which may require some critical thinking and stress, yet it's college

I would say his exams were more fair than my professors in 21A and 21B. Great professor the only problem I have with the class is a quiz a day before finals. He should show the physics department how to actually teach properly since Professor Challenor is actually nice, clear, and helpful.

I know he is very kind and respectful professor, but he can't be the reason of some students depression. We all know math 21c is hard then plz give us some good practice problem so we can be fully prepared. I can't be depressed anymore no sleep or food 24 thinking and studying to fail the final

what a comeback

I have always struggled with calculus and won't do too well in this class, but this class is great for people who will take math beyond 21C. Prof. Challenor is an engaging lecturer and does his best to teach the concepts instead of memorization. His homework is comprehensive. My only wish is that he posts homework solutions before quizzes/tests.

Amazing and caring professor who is super passionate about math! His lectures are very easy to follow and he provides many problems to help you study for the exams. He is super kind and helpful during OH and goes out of his way to make sure his students understand this challenging course.

Prof is super good (i just didn't put enough effort towards the end). To do good in his class do all the homeworks, go to calc room and truly understand the concepts, and utilize all the resources you can. Also go to office hours as he teaches complicated concepts really well. Essentially, easy to pass but put in hard work for a good grade.

Professor Challenor is a great lecturer, gives a LOT of homework that is very comprehensive and in depth, making it easy to fall behind/miss key concepts if you don't have a lot of time to study. Exams are difficult, you'd see the types of problems found on the homework mixed in with theoretical ones with an emphasis on concepts. Very fast paced.

nice guidelines, so just do your hw and go to lectures. easiest way to boost ur grade is to get perfect scores on all quizzes (not hard)

Look I am going to be as unbiased as possible. He is one of the best lecturer and great person. He really does care for his students and answers online regularly. However both of his midterms were harder then it need to be, but his final was very easy and fair. I took him both for 21A and C, and think he is a great teacher, but his test are HARD.

ngl his class was difficult and i failed the first midterm but i did well on the final exam (around 90% iirc). He grades stuff harsh though, and I still don't understand how grading works and how i got an A

2 Exams 40% Final 35% Weekly Discussion Quiz 25%; HW after every lecture's optional but Quiz problems are similar to HW so beware. Exams are theoretical & hard (averages are 50%) BUT if u score higher on Final it replaces both midterms so theoretically u could bomb both midterms, get 90 on final & that 90% replaces midterm scores. An A is possible

Loved this class! It was difficult but I really appreciated Prof Challenor's energy at 8am, it made lectures more enjoyable :) He is quite generous with partial credit but the only thing that sucked was having no formula/cheat sheet or a calculator so you'll have to memorize but exams are doable if you do the exam reviews and homework.

The absolute best math professor.

My beautiful bodacious brave king Challenor. This man is what Jesus strives to be, he is the universe's gift to us mere mortals. GO TO HIS OFFICE HOURS!!!!!!!! Do his homework, he will help you to the best of his ability.

Super nice understanding professor. Tests can be somewhat brutal, but if you actually do the reviews before them you'll be fully prepared because the tests are basically 1:1 with them. Highly recommend this class.

He's nice but exams a bit hard

quiz every week in the discussion, exam hard

Really can't ask for a better professor for the MAT 21 series. Gives very clear lectures that are recorded, also provides tons of optional homework worksheets that are great for studying. Weekly quizzes are a bit of a pain but they force you to stay on top of the material. No curveballs on tests, as long as you study what he teaches you'll be fine.

HE REALLY LOVES MATH

His lectures are THE BEST. Really passionate about math, and he does plenty of Zoom review sessions prior to exams. You are also given review problems prior to exams, which were super helpful. His exam questions are almost 1:1 to homework and exam review, so make sure to do them. Weekly quizzes, but they aren't too bad.

This guy LOVES math, and he is definitely a challenging professor. Two midterms and a final exam, 8 quizzes (2 lowest dropped), optional homework and curve final grade cut-offs. His lectures are very clear, and he explains hard concepts well, but if you're struggling: SIGN UP FOR CO-21A. Be prepared to do lots of homework and practice worksheets.

Hes a nice guy and a good prof but after i saw my final exam grade i had to immediately get high.

THE BEST. Professor Challenor is a rarity of a Professor, AMAZING lectures, content is not easy but 1) show up, 2) take notes, 3) do the homework, 4) office hours, 5) ask for help, and appreciate the beauty that it is this class. My TA wasn't wrong, 21D is absolutely my favorite. (Professor Challenor, PLEASE teach physics and engineering T_T)

I thought Prof. Challenor was excellent. His lectures are amazing, and he has four office hours a week which really helps. While the exams were challenging, he gave good partial credit, and the exams were fair. Overall, he's the best calc Professor I've had at Davis and it's obvious that he cares about a lot teaching and his students.

Somewhat easy quizzes each week, but hard midterms and final in my opinion. He teaches very well and you can tell that he's passionate about the subject. The only thing I would take away from him is that in lectures he goes over very easy and simple problems but his HW and tests make me feel like I have no place in this class sometimes.

He is a very passionate professor and is very accessible outside of class (4 OH/week). I found his tests, especially the final, very difficult. Homework is not a part of the grade, only the weekly quizzes, which are based on the optional homework (1 for each lecture). If you are not a good test taker, I would not recommend him as a professor.

Great professor who is extremely passionate about math and genuinely wants his students to do well. However, I feel like he can overestimate some students' abilities, and it can be difficult when the easiest homework problems are already challenging, making practice hard. But, lectures are great and he hosts many review sessions so you can do well.

Challenor clears Lebron and MJ.