Very easy to understand. VERY helpful. He has an ability to present the material in a very organized and understandable fashion. Plus he is a cool person, jokes around in class, etc. If you have to take MATH255B, tkae CASTRO!

He is very helpful and good. He knows what he is doing and easy to understand. Material is kind of hard but he makes the work easy.

A great teacher and patient. Handed out math-related comics along with our assignments, e.g. Calvin and Hobbes doing homework, just for fun. Y, as in Y do we care?

easy going and helpful in the office =)

The best math teacher i have ever had. Very Helpful, very clear and reviews the homework before grading it. Tests are on material covered in class and has a revies sheet for most test. Definitely take Castro.

I can't be more thankful for this class. Castro has ultimately "redeveloped" my math skills that were, so I thought, forever lost in highschool. Brilliant and so focused as a math teacher, he seems to make everything so understandable.

he welcomes questions of any type. He won't make you look stupid for any reason. Great teacher.

Definitely the best math teacher that i have ever had.He is as clear as a rock, i dont know how to say it, but make sure u take Castro for 255A. Every student gets what they deserve.This is not to say he is easy, that would be a wrong impression.Good guy

He is not easy, but very good. He is very helpful. He will help you until you get it. He really cares about his students. If you need to take a Math class, he requires a lot of hmwk but if you need to pass he will explain things until you get it.

Thank goodness there's still a teacher that can teach! He goes slow and he makes sure his students understand!He'll answer students questions and think how he can explain it more clearly. Tests aren't hard since u can undrstand his lectures. Great teacher

What can I say, they have said it all, Castro is awesome, and it is not that he is easy. No, he is just very good at explaining and ensuring that everyone gets the material. A true teacher with a kind heart. Also very smart. Just love him, no question, if it is calculus, take Castro.

Best math tescher ever! Super helpful, totally explains all material until it's understood, tests reflect notes and homework.

I HATE MATH, AND HE MADE IT BEARABLE AND SLIGHTLY INTERESTING ACTUALLY. HE TRULY CARES THAT U GET THE STUFF AND THAT IS MOTIVATION IN ITSELF. BEST MATH TEACHER EVER!!!

i loved math after i had his class, math had never been this easy for me before, the best thing about him is that he keeps us in his class with him doing anything i am gald we have a teacher like him

Best math teacher I've ever had. Failed the class first time around because my teacher went too fast. Castro takes his time and does what ever he can to help his students.

He is the best math teacher I have EVER had. His love for the subject really shows and you can tell that he really wants to get his students to understand. Not only is he an excellent teacher, but he's a truely nice person. I hope that I can take a class with him again sometime.

Hard class but if you come to class everyday and listen to his lecture, you should do well.

Whether you love math or hate math, he is the best teacher I have ever had in my entire life. The first time I took Math 102 I did not pass the class, the second time I took it with him and I passed with an "A" He is not easy, but he cares for his students, and if he sees you are will to learn and

TAKE CASTRO!! FOR SURE!! He is a very easy going guy. He is understanding, nice, and extremely helpful. He will help you and help you and help you until you get it. If you hate math and have to take it, he'll make you at least respect it, and learn from it. Seroiusly one of the BEST MATH TEACHER'S!!

THE BEST MATH TEACHER EVER!! Although some say that math is hard, he makes it easy. He explains it very well and clear. Gives examples so everyone can get the discussion. Lets you go to his office so you can ask him questions. Must attend class everyday to get good grade. Test and quizzes easy.

He makes math easy and clear..his quizes are based on key concepts of the chapters..He makes quizes and tells us what to study for..and for the test the questions are similar to the ones you studied for in the quizes..I recommend this class to everyone..He'll help you pass if you put the effort

THIS CLASS Is EASY..((yOu HAVE tO dO is SHOW uP tO CLASS EVERYDAY THOUGH))...HE GIVES KEY CONCEPTS REVIEWs TO STUDY FOR THE TESTS and they're THE SAME EXCACT CONCEPTS...HE GOES OVER EVERYTHING AND EXPLAINS IT WELL...HE EVEN TAKES HIS FREE TIME aSide from HIS OFFICE HOURS TO HELP OUT STUDENTS!!!...

This is the best math teacher you will ever have. He actually makes math easy. He is well-tempered and very helpful A++

ilove Mr Castro!

personally, he was allrite..he tended to put problems in the very end of chapters on the test..that ones that were kinda of tricky...i didnt like the selection of problems he put on the test at all..i didnt think they really tested our full knowledge on the material

He is the best of all time.

I'd be cautious about these comments. Yes this Prof. is a very good teacher, but the class isn't all that easy. There's a lot of HW, 3 Tests, and a Final. Tests are challenging and he's not an easy grader. If ur taking 255B this is a good class b/c the guy can teach well, but getting a good grade is a challenge.

he is great guy. Take the a class form him if you get the chace. You wont regret it

Nice guy. Works hard to teach you the material. The class isn't easy though, but if you show up and work hard you can get a good grade.

Great professor!!!! Very helpful even thought the class is not easy. Takes time out of his schedule to help and clarify material.

He is very hard but a good teacher..he knows how to teach and he does concept in depth and his tests are very hard..dont take him if u cant keep up with the homework and learning concepts...if u r not great at math then u'll most probably repeat..take only if u r a very hard worker...from the beginning though :(

AWESOME TEACHER!!!!! USE HIS OFFICE HOURS

This is just a hard class to teach. . . and understand. His tests are kind of hard and he doesn't curve. He is very very helpfull if you go to his office hours though.

For this class only he curves grades. Exams are based on hwk and class work. Hwk is easy. The most important thing for this class is: DO YOUR HOMEWORK ON TIME. If you read only 20 min ahead before each class lecture you will be on top, guarantee for this will help you with your class work and on following his lecture. He moves at students' pace.

A Lot of info. but prf. gives testes based on what he tells us the test is on. Hard class good prf. You actually learn something.

Is a cool guy. You pretty much have to attend all the lectures, do and for the most part understand the homework, go over your notes constantly and know the theorems and proofs for the tests. Definitely not easy, but you can learn a lot from him if your willing to make the effort.

Greatest math professor!!!!! I hated math but prof. Castro expalined it so well that now I love it!!! Attendance is mandatory if you want to pass the class. Exteremly helpful and always available during office hours. Quick reply to emails. Take this professor.

Really cool professor, beats the hell out of any other ones teaching at csun

Prof. Castro is an amazing teacher. Explains everything clearly though classes can get a little boring. Extremely nice and easy going. Did not really need the textbook due to online homework assigned. Definitely reccomend him, i got an A on the final and the class.

Prof. Castro is a great teacher, he always tries his best for you to get the highest grade u can get if u meet him half way there. If any problems with the course happen, just talk to him and always makes things easier on u(the student)

Awesome math teacher, I highly recomend him. If it were possible I would take him for every math course offered at csun. Has real good way of teaching the information without confusing you.

Professor Castro gave a clear lecture and gave plenty of good notes. I remember going to him after the midterm for help and he helped me in a way I could understand. He was always trying to help people ion class and was always trying to boost the morale of the class. The class is a bit difficult so study hard.Professor Castro is a good guy

I love this guy! He's great at explaining the lesson in a way that you will understand. He encourages you to ask questions and he answers them perfectly. I wish I could take him for every single math class at CSUN. TAKE HIM!!!

this is my 3rd time taking him for diff math classes. recommend to everyone, very knowledgeable professor. explains everything clearly and is a fair grader.

easy to follow and fun to look at.

There's really nothing more to say about this professor other than what is already posted. He's extremely calm (a little too calm)..his notes are very very clear, he answers all questions..the course itself may be confusing, but Castro will not throw you off guard with his tests, whatever he has lectured will be on the test

Hes a really good math professor. Explains everything very well and he is always willing to answer hw questions. He makes math a lot easier.

Great Teacher. He really cares about his students.

Best darn math professor i've had in a long time! Very clear & takes the time to actually help you understand the material. Very hard grader, like very picky about how certain things have to be but it helps in the end cause it helps you learn the RIGHT way of doing math. I would recommend anyone to take him. AND he's not too bad on the eyes (;

Take him best professor ever

Has a problem with people coming in late or leaving early. Tests are very hard, and unfair grading on top of that. Gives out a ton of homework, and barely gives you enough time to do them. Keeps you after class to do group work that isn't even mandatory. AVOID

Great professor. Take him!!! He writes the tests for math 102 and 104, so his tests are what the final will be like. Review the homework, and do not come in late. he takes attendance randomly, and you better not leave in the middle of class. Very helpful. And may drop lowest test score. 3 tests, 1 final and H/W, classwork, and other random stuff.

A really amazing professor. He doesn't hand out good grades like candy, you have to earn them. However, he is extremely helpful in all aspects. He doesn't make you feel stupid at all when you ask questions, and helps you loads during office hours. Can be funny at times, too. He's not 'easy', but he definitely knows how to teach. Best math prof.

Castro is so sweet. He's soft spoken and speaks slowly and clearly, making sure everyone understands the concepts. He gives numerous practice material that is very similar to the test, and is very straightforward with the material. I wish all my math and chem teachers were like him.

This is the best math teacher you will ever want to find. He taught me all the math that I know and I even had classes with him in Jr High School. He continues to be an excellent professor. You won't be disappointed.

Castro is the epitome of a great math professor. He is so clear and shows interest in wanting to help you understand. He is rather soft-spoken but it's *to make you listen*. Haha. Excellent Professor! I HIGHLY RECOMMEND!

Castro is amazing. I HATE math because I am terrible at it, but luckily I had him for 102/104. He teaches everything clearly, his examples/hw are almost always what will be on exams, and he writes the common finals. I'm bad at math and didn't get anything short of a B+ on any of my exams. Your grade(s) in the class will reflect your efforts.

he's a tough grader. Hardly any partial credit and if you make a small error, he will remove a huge chunk of pts. Also he's very discouraging. first day he said "only 15% of you will pass." last week of class-"The final will be the lowest score for most of you." Studied my butt off and got low C's but I'm bad at math. Don't take if you suck at math

Avoid if you suck at math (or want an A or B). Some got C's and a majority of the class didn't pass. No curve, and a very tough grader.

Castro is a great professor even through his grading can be a bit harsh. It's one of those classes where you absolutely cannot miss lecture and it's also a class where you MUST do your homework in order to fully understand the material. I recommend him because his explanations are clear and his harshness pays off during the test and the final.

Greatest professor ever! Feel like I Can teach the material now. He really explains everything well enough to get the material perfectly. I wish he taught higher level classes. I got an A on the final thanks to him.

He is a great professor. I wish he teaches higher math levels. He teaches clearly and his test can be easy if you do the homework and the quiz.

Best math teacher I have ever had. He will always stop to explain something no matter how simple as long as you ask. Before a test he gives you exams from previous semesters for practice. I never had this math in high school, and I got a 95% in the class. There are 3 tests (20% each), a final (30%), online and in-class homework (10%).

He's The best teacher I've ever had..!!

A really good teacher. He is on top of his stuff. If you want to get an A take this class.

He is great pro. He explains anything you ask. Before each test, he gives review and for the final just study the reviews and you will take at least B-. I got an A

He's the best math teacher I've ever had .. thank u professor Castro!!!

Best math professor ever. The material is difficult but he is not. Will explain anything you are confused about, no matter how simple it maybe online homework assignments on every section and quizzes on every chapter. In class exams and a common final. Very highly recommended especially if you are very bad at math he will be very helpful

He is a great teacher. His tests are very hard though. You will not pass if you do not study. As a teacher though, great guy. I would recommend him.

hes nice and is very helpful but thats all he really is. he is super tough grader, made some small errors like [] instead of () and took almost 90% of that question grade points off. do not take this class if you just need math credit, take something easier like math 131 or 210 or stats. more than half the class fails this class

He went through the topics very quickly and the tests were pretty hard even though he gave very easy examples when teaching the material. He said that nearly half the class fails each semester. #IAmThe1/2 ._.

Professor Castro is a great professor! I will agree that his tests can be hard only if you do not study. If you think you're gonna pass by just knowing the material, you're wrong. You will need practice problems on your own to do good on the test. But he is very clear, and is willing to help at all times! Highly recommended.

very easy and laid back professor. He teach at steady pace and will gladly answer any questions you have.

He is awsome!!! <3

Great professor, very clear. His tests are only difficult if you don't study/pay attention. Homework is mostly online, and if you have a question he will be sure to answer it.

I have always been very bad at math so of course I knew the class would be a challenge but Professor Castro went over everything thoroughly. He was not judgmental and encouraged questions. There are a total of 3 tests in the class plus the final. The first test was multiple choice but the next two were written. I passed with a C But it was hard.

I liked Prof. Castro! But his tests are VERY hard. He emails the class study guides before each test, but make sure you study your notes as well as the study guides. He picks the trickiest questions for the tests, so be sure to study the examples you thought were hard (from your notes) because those questions will most likely be on the test.

I found that if you haven't taken Math for awhile, you really need to get up to speed first. Self study is a must. I used Youtube videos. Do the homework assigned and ASK questions when you don't understand. Castro teaches shortcuts, which is great, but I need to fully understand something before I learn shortcuts. Castro is very helpful.

He is the best when it comes teaching math. He is very knowledgable it what he's saying and explains it in such a way that you will understand it.

Best math professor I've had at CSUN, really knows his stuff and makes it easy to understand. His test are hard and require you to not only know how to do the problems but understand the reasoning behind them.

First off let me just say that this class was the hardest math class I have ever taken. The tests tend to be a lot more difficult than the hw, so you must UNDERSTAND everything. 70% proof based. He was also either always very late or absent during his office hours. With that being said, he was not that bad. Bring your A game or you WILL FAIL!

He was my first math teacher for math 102, the course was hard and easy at times depending on the section. I'm a mechanical engineer major and this class was pretty tough but he is willing to help you. He's pretty chill and cool.

Very clear teaching style. All you have to do to pass the class is show up and do the reviews for his tests. Tests can be hard sometimes but just study. Great at answering questions. Grading scale is normal No curves. Online homework and quizzes for each chapter. In class tests are all about 10 questions each. SHOW UP TO CLASS

Best math professor ever!!

I've taken Castro for both math 102 and 104 and he is hands down the best math professor available at CSUN. He is the head of the math department meaning he is the one who makes the final for all the 102 and 104 students!!! I've never had anyone explain math so well. Attendance is key though. He takes role everyday.

Pros: Very nice, calm, and clear. Tells you what to expect on the exams. His test reviews are almost spelling out what will be on the test, but don't get cocky, because 50% of the test is pretty tough. Cons: Late to office hours regularly. Doesn't curve Overall: If you enjoy math, andor are serious about it, take him. He's really great

Assigned review packets prior to exams which exactly contained what was going to be on the test, literally. Don't think he was very organized with regard to homework. Lectures are slow and smooth which gives you ample time to digest the information. HW was definitely harder than the exams

Professor Castro class was so nice, I took it in the summer and the only problem was that we take everything so quickly. His lectures were clear if you focus with him. You must do the homework to do well in the exam. 3 test and 1 final. He was so helpful, you must study to get a good grade!

In linear algebra he expects so much from the student. It is all proofs so you need to know the subject conceptually like a pro. If you are taking linear algebra just because your major requires you, take someone else. If you really want to learn linear and spend all your time understanding the deep concepts and proofs take him. He is a genius.

His lectures are very clear. He does motivate his students. As long as you PAY ATTENTION to the lecture, you will pass with an A guaranteed!

Best professor ever! He is very clear with the lectures, he explains every problem that will be on the midterms. If you are willing to pay attention in class, there is no way you can't pass with an A!

The lectures consist of him reading off the workbook and doing example problems. His test are some what difficult but gives a study guide for each of the three test you take throughout the semester. When finals approached he held a study room separate from the regular days of class. Overall, if you put the effort you should have no problem.

He's very good at explaining the material, and an easy grader for the homework. However 262 is still a very difficult class; the second midterm and the final are the most difficult. Book can be found online.

AWESOME TEACHER!!!!!!!!!

You won't regret taking him he's a great professor. He's also a major hottie!

Prof Castro really is a great professor. LA is a really tough class and he explains it well, but the tests are really tough. It would take many hours of studying per week to do well in this class. This was my second time taking LA, and I now have to take it a third time, but if you study hard you will have a great foundation in this subject

Honestly the best math professor by far! Really works with you to make sure that you do well in his class and is willing to spend one-on-one time with you. He is also such a cutie! I wanted to take him for Math 104 but sadly he wasn't teaching. Take him! You totally won't regret it!

best math professor or teacher I've ever had. I failed Math 102 my first time through because my previous prof didn't teach much of the material because she assumed most students covered it in high school (???). Castro clearly explains everything, takes the time to answer questions in class, and doesn't rush through the lecture.

He's very skilled in mathematics but he doesn't act cocky like most math professors. He's caring and very patient with his students. Just a real gem. I feel so lucky to have had him as a professor.

The most amazing math teacher I have ever taken. He really listens to you when you need the help. He really knows his stuff. always willing to give more help, very clear and if you do not get the first time he explains it to you over again in a different simpler way.

A good math professor. Always answers questions politely and cares about the class. Weekly homework given on XYZ online math program w/ 3 chapter tests and a cumulative final.

he's a good professor, but if you're terrible at math, don't take him.

Really great math teacher that cares for his students. He goes through lots of examples that made the questions in the book look easy. If you do the review handouts that he gives for each test and understand each question, you should be able to pass the class

Professor Castro is a great teacher. He doesn't speed through the work, but rather shows everything step by step, explaining everything in detail. Definitely wants to help every student understand the material and pass.

Professor Castro is an amazing professor, very approachable. Failed the first time passed w/ him. His lectures are very straightforward and easy to understand, goes step by step. Don't slack, keep up with what he's teaching, he's there for a reason so go to him. 3 test + cumulative final. Attendance matters as it is counted as classwork(10%)

Professor Castro has been my favorite professor at CSUN, and by far my favorite class, which is ironic because before him I absolutely hated math. He will make you enjoy math, and he is also very patient. He once said " people who are smart are talented, but for others its all about being persistent" and that has gotten me through college.

Amazing professor. Go to class it is the only way that you will learn. He made me want to do good in the class and I really appreciated his class.

He is one of the best professors that I've taken. His lectures are simple and very easy to understand. He explains all the material easily and clearly.

Take him. Helps you understand everything. Go to his office hours as well he really cares about the grade you earn. Love his teaching methods.

Take him, take him, take him. He explains EVERYTHING clearly and cares about your grade. I'm upset because he teaches Math102 and Calculus 3! I'm currently in Calculus 1 and I'm super butthurt that he doesn't teach Cal 2,3.

Castro was the best professor that can teach Math 102. He always goes over little by little of how to do the math correctly. Of course, Castro will always help you out. All tests were from the chapters you learned. Homework was online, which students hate to do it, but it's worth it and can raise the overall grade. Take Castro. You won't regret it.

Prof. Castro is really good at explaining, he goes step by step so you could fully understand what is going on. For M102 there are only 3 CHs, so you'll only get 3 tests throughout the sem. but they're difficult if you don't study. When you don't understand something, I'd recommend to ask questions in class, go to his office hrs, &amp; go to tutoring.

Excellent lecturer, very easy to follow. Went in expecting the class to be very difficult, and while it is definitely a lot of work and kind of abstract it was a breeze thanks to Castro. Lots of homework to keep up with, so be prepared. Tests are straightforward, wasn't surprised by anything on them. Would take again

Honestly one of the best math professors I've ever had. Explains everything clearly and truly cares about his students. Answers all the questions the students ask and won't move on unless they understand the question. You do have to show up to class and do the homework on time, he also gives you 3 late passes for the homework.

I personally never asked for help in class but he was already ready to answer any questions in class and even encouraged students to email him for help or to attend his office hrs. For tests, doing ALL of your HW as soon as possible and going over his study guides should get you a good grade. I slacked off at the start and wound up really hurting.

He's an awesome professor who really does a good job at teaching what he knows, lectures can get a little stale at times but he has very reasonable expecations that arent that hard to meet. Make sure you study for the 3 tests and Final

He is a great Professor. Although, he does get mad when students leave to go to the restroom. I would recommend this course because he really takes his time to teach and he makes it very simple.

He is a great Professor and really wants all his students to excel. Although, he does get mad when students leave to go to the restroom which is a bit nit-picky on his part but it's because the door makes a disrupting loud slam. I would recommend his class because he really takes his time to teach and he makes it very simple.

AMAZING PROFESSOR! I think his way of teaching is at a perfect pace for everyone to keep up. Do not take if you hope to miss class, do not take if you hate turning in homework, and do not take if you have the bladder of a squirrel. He dislikes when people leave the classroom. It's rude! But overall Great professor! RECOMMENDED!

He is an amazing Professor. He made calc 3 easier than what I expected. His tests are more tricky then difficult, so make sure you study whatever he specifically tells you to go over before an exam. Highly recommend him for any math class at CSUN

Professor Castro is amazing and so helpful. Go to his office hours ask him anything you would want. He was able to teach the material in a month a half comparing to the fall material it takes the professor to finish it in a longer time. I traveled and missed 3 days and I was able to pass the class.

Having taken Calculus in high school, this class really refreshed my memory on certain topics. Lectures so good that he answers your questions before you even answer them.

I am taking him for calc 1. He lectures very well! Answers all your questions, sometimes he conplicates his answer but he will always clarify more if you need it. He gave us study guides. He does give LOTS of homework from the textbook. Does not grade on a curve, takes attendance, gives you options at the end to bump your grade. Highly reccommend!

James Castro is a gem. If you want the secret to get an 'A' in this class YOU MUST DO ALL THE HOMEWORK ; YOU MUST GO TO ATLEAST 1 OFFICE HOUR EACH WEEK TO GET PROOFS*CHECKED. ; YOU MUST STUDY THE PRACTICE TESTS/PROBLEMS. Do that get an A. PROOFS ARE SOOOOO IMPORTANT. You MUST!!!!! go and check if you are doing the HMWK problems correctly

Professor Castro made me love math! Hes incredible and he made math easy to understand. Would totally take him again if I could!

Showing up for this class is extremely important. The homework assignments are similar to whats on the actual test which is really helpful, and does a good job preparing you for the final.

Prof. Castro is such a chill and friendly guy. His lectures are good and he is very patient with people's questions. The tests are pretty straight-forward and he gives plenty of time to complete them.

I highly suggest that you send in your proofs to him. He even tells students the first day to send them in because they can be quite challenging and the class is basically proof based. He is good with accommodating to your schedule if you can not make his office hours. Homework will be assigned from the textbook.

show up, take notes, and study the examples he give in class you will get an A. his lectures are super clear and organized. i wish all the Calc professors are like him.

Castro is an amazing professor. He is very approachable, patient, and wants his students to succeed. His lectures are very clear and he always checks to see if everyone understands the material before moving forward. Would recommend him for any math course. If you pay attention in class and aren't afraid to ask for help you should be able to pass.

By far, the best math professor I've taken to date. He has unending patience, cares to make sure everyone understands the material, is extremely approachable, and offers a huge extra credit opportunity for those who participate. If you're looking for the perfect math professor, you've found him.

Expect lots of self-studying! Youtube videos help! He gives reviews and past tests, which I find are most helpful for the tests and final. Pay attention to the examples in class! (Especially those he says will show up again!) GO TO HIS OFFICE HOURS, YOU WILL NOT REGRET IT! Overall, very clear and straightforward professor! Would take him again!

Professor Castro is an outstanding teacher. I took him for online classes and he always answered questions and went above and beyond for his students. Linear algebra nisna difficult class but professor Castro does his up most best to help

Castro is an excellent professor to have for any math course. His lectures are very organized and he explains concepts in the simplest way possible. He truly dedicates his time and effort in making his students understand each concept. The level of patience he has for answering questions is incredible. I'm very grateful to have him as my professor.

Great teacher. Very thorough in teaching to help students understand material. 10/10 teacher would definitely take again.

Professor Castro made calculus so much more easier!!! He is very lenient and cares about his students even through Zoom. Just do the homework and study for the exams and you will pass. He goes over exam material beforehand so there are no surprises. This man needs a raise! By far the best math professor Ive had.

Castro was great at explaining complex topics of linear algebra. He was very caring and spent a lot of time answering questions/reviewing for the final exam. Used mainly xyz for assignments, some textbook assignments, and 1 problem presentation. It is a hard subject, but if you put in the work you will succeed.

He is a very good professor. The material is hard and he tries very hard to make it easy to understand. He happily answers questions in and outside the classroom. By far my best math professor at CSUN. I would definitely recommend taking him. Although this is a hard class, so you should definitely get yourself a buddy. Required effort for an A.

Professor Castro is great at explaining linear algebra concepts. The class is challenging, but he's very helpful in office hours and encourages using resources like the textbook and unstuck study for extra practice. With consistent effort, you can definitely succeed.

imo he grades a little too harshly especially on the take home quizzes. the quizzes are your best study guide for the 2 Midterms and final. You can take 1 cheat-sheet front and back to the final exam which is really useful. His lectures are great and very understandable