Such a wholesome guy. Take him if you can.

Can't recommend this professor enough. Wenhao's exams were almost identical to the practice exams he gave out, with just the values changed.
He is a little sparse on communication (he doesn't use CCLE) so make sure to attend lecture or make a friend that attends lecture to stay up to date. Or don't, you'd probably be fine that way, too.

Professor Ou really cared about his students, and he actively tried to make sure that we understood all the concepts. He did have a strong accent which made him hard to understand but his tests were honestly really easy if you just understood the basic concepts. The questions on the exam were not any harder than the book problems. The only thing is that he had an accent that was really difficult to understand.

Do not take this class. Even if you have taken calculus before, you will likely not feel prepared to answer exam questions without your TA's help. I learned everything from my TA, as lectures did nothing to help me learn or prepare for the exams. The professor often mumbles unnecessary proofs for the majority of the lecture, leaving you confused, bored, and unprepared. To summarize, the curve at the end of the quarter allowed a 30% to be a passing grade in the class due to the poor performance of the majority of the class.

Honestly 31A w/ Ou was a breeze especially since I took AP Calc in high school. The 2nd midterm for this class was really hard though ( avg score was 57%). The first midterm and final were pretty easy though. I got used to his accent pretty quickly. He was pretty good at explaining everything. The TA(Stone) was super helpful.
If you study the practice midterms, do the homework, and go to class(take notes) you should be able to get an A

I took Math 31A with Professor Ou, and it was pretty easy for me as I took calc in high school.
His midterms were incredibly similar to the practice midterms he gave us. The first midterm was super easy and the second one was a lot harder, but just work on the practice midterms beforehand and you'll be fine. You can drop one midterm as well so don't worry!
The homework load is also pretty light (less than 20 questions a week).
Overall, if you go to lecture and discussion, take notes, do the homework and practice midterms it shouldn't be too hard to get an A!

Ou has good intentions, but I didn't enjoy or learn much from this class. For your own sake, please avoid taking 31A with him if you haven't taken calculus before. It's worth noting that you cannot use calculators during exams, though this might be a departmental thing.

He has an accent, but that isn't the problem. The way he explains things is generally confusing, so I had to rely on the textbook and the things I'd learned in high school. Before this, I honestly didn't think it was possible to get worse at a subject by going to class. About halfway through the course, I stopped attending lecture altogether and only showed up to turn in homework. (He collects it at the very end of class, which is nice.) The TA did a better job of teaching the material during discussion, so be sure to attend that if you're really stuck.

The homework was pretty easy (<20 problems per week), though my TA tended to nitpick over answers. Ou often assigns the harder problems from each chapter, and roughly half of them are even problems (which have no solution in the back of the book).

The midterms were weird. One was very easy and exactly like the review, and the other was just unreasonably difficult. Ou sent out practice tests about a week in advance, but he didn't always provide the solutions.

The majority of the final was (unsurprisingly) different from the review, and was still quite hard since the problems weren't anything like what was assigned for homework. Since pretty much everyone failed the final, a 30/100 was considered passing. (Yes, it was that bad.)

One nice thing about this class is the grading curve - according to the math department, the top 25% gets an A, the middle 50% gets a B, and the lower 25% gets a C or worse. Ou offers two grading schemes (the higher of the two will be used) and they are as follows:

10% Homework + 30% Best of the two midterms + 60% Final exam
10% Homework + 25% Midterm 1 + 25% Midterm 2 + 40% Final exam

Also, his name is pronounced "oh", as in "oh my god why didn't I switch classes when I had the chance 🤦"

This is for Math 31A. As someone who has taken Math 31A with two different professors, I feel like the rest of the people who reviewed Ou for Math 31A hadn't experienced how terrible UCLA math professors could be and I feel like this review is more accurate based on both of my experiences.

I had Brizolis for 31A Fall Quarter, and he made what was supposed to be a AP Calc AB review course into an impossible-to-pass class. His exams were extremely difficult, and nothing was curved. I received a C- in his class, and I had to take 31A again - I have Ou this quarter.

The rest of the reviews are accurate in that he has a strong accent, and tends to not speak clearly which takes some getting used to. However, his grammar and spelling is good and he writes out everything he says on the board, so as long as you take good notes you'll be fine.

However, his class is MUCH more reasonable compared to Brizolis's; there is only one homework assignment per week, the exams are almost exactly like the reviews, and they are not overly difficult. He does not teach or test on proofs like Brizolis did (no delta/epsilon limit proofs!), and can be reasonably finished in 50 minutes.

I honestly get very irritated hearing current students complain about Ou's class, when he is actually a fair lecturer. If you have already taken calculus in high school and are good at it then I highly recommend taking Ou - it will not be hard to get a good grade. If you need more practice or haven't taken calculus in high school I would recommend maybe a different lecturer you can understand better, but if you have to take Ou then just copy what he writes on the board; it won't be the end of the world.

His class is not bad at all and while I struggled to get a C- in Math 31A last quarter, I am easily pulling A's in Ou's class.

I'm just going to say it: Ou is a shitty professor. I honestly have no idea what he is doing teaching a class. It does not seem like he enjoys teaching and I think he should find another career choice. It didn't list him for Math 31A so I'm listing it here.

Lectures: He is extremely unhelpful during lecture. He tends to go into extreme technical detail about the concept rather than examples of the concept. I took Calc AB in my senior year of high school but got a 4 so I couldn't pass out of this class. I think the only reason I did well in this class was because I had literally already learned all the material. Sometimes his lectures would be so confusing I felt like I was unlearning. He teaches facing the board and rarely turns around to see if there are questions. People would raise their hands for ten whole ass minutes and he would not turn around to see them. If you have a question I would recommend shouting it because otherwise it will go unanswered. He is slightly more helpful at office hours, but still very awkward/unapproachable. I almost feel bad for him. Almost.

Grading: Homework load is not that bad. Tests are very hard, and that means the curve is strong. I know a lot of people who took this class, got a horrible grade, and did not go on to Math 31B. I got Bs on the midterms and the final but because of the curve that got bumped up to an A-. However with the curve it is very hard to predict your final grade in the class because it is based on the grades of other students. The entire quarter I had no idea if I would get a C or an A.

Tests: Study hard for the first midterm because the second midterm will fuck you up. Ou does this thing where if you fuck up one of your midterms, he will drop it, but your final grade is weighted more so that means if you deeply fuck up one of your midterms you have to really study hard for the final.

Studying: The one positive thing is that Ou's study guides are identical to the format of the final. So if you can master the type of problems given to you on the study guide you can do well on the midterms.

Sometimes I think I'm being too harsh on Ou but then I remember I hated every moment of this class. It was only when I got to Math 31B that I realized not all UCLA math professors are shitty.

Math 31A. This class was really easy and I put practically no effort into it. He is one of the easiest professors but he struggles to teach, so if you have a good background in math/calc I suggest you take this class. Like I said he stunk at teaching and wouldn't even go to class every week. If you just study past midterms and finals it'll be easy but don't expect to learn anything new or be well prepared for higher math.