Easy class, confusing lectures. I had to teach myself most of the course material because Professor Tang had a very roundabout, complicated teaching style. (To be fair, it was his first time teaching, and he definitely improved over the course of the quarter.) One thing I did appreciate were the timed in-class examples we did, because I would already have some kind of idea of how to approach problems for the homework we had. We had about four homework assignments the whole quarter, and the midterm and final were both very straightforward and simple.

There are 3 parts in 170A: basics, discrete random variables, continuous random variables. Tang initially said there should be 5 to 7 homeworks. However, it turned out that he only assigned 3 homeworks altogether which correspond to the 3 topics.
Test is not hard except for the last question(which is optional if you have extra time). Questions are all from lecture notes, homework and practice exams, with a little change. I honestly don't get why most people scored badly in the exams because questions are all quite familiar. A one-page cheat sheet is allowed for each exam.
Overall, Tang is a great lecturer who teaches very clearly and is generous with giving As.

Do not take this class with this professor. Going to lecture will be a literal waste of your time because you can’t understand a damn thing he says or writes, and he goes so fast and rarely explains questions well. I’ve had to teach myself everything I don’t know out of the book or from office hours with my TA. Its easy because you get a whole page cheat sheet for tests, but literally did not learn a damn thing on the sheet. He’s one of the people that makes me ask myself: where is my money going? Is this really what im paying 34,000 dollars a year for? Shame. Shame.

Took this class coming from AP Calculus BC, so I already had a general grasp about the material before hand.

Tang is a confusing lecturer. He often skips steps when doing practice problems and his way of explaining proofs for the topics are near incomprehensible, which makes it vv difficult to follow along. If you don't know the material before this course, you would probably have to self teach the concepts w the book, but I heard he's pretty clear when you ask in office hours. While Tang is not the best lecturer, he has a very light workload. I think there was a total of 4 homework but 3 were turned in and only 2 were graded, the last one was also just practice for the final.

For his midterms, you always get a single sided cheat sheet along with any calculator. His first midterm was practically identical to the practice midterm he sent out(median was 90%+), while the second midterm was significantly harder than the practice ( the median for it was like 60% ). For his final you get 2 cheat sheets (front and back) but no calculator, and that final was ridiculously harder than his tests before (the median was around 40-49%) . I would only recommend taking his class if you have a strong grasp of the material beforehand, otherwise you should take another class.

I haven't taken any AP Calc before so most of the materials in this course are new to me. Honestly, Tang is not a very clear lecturer. He might be hard to follow sometimes, but when you get used to his style you will know what steps he skipped when doing the problems, and those steps are really not that hard to understand. The workload is really light. We only turned 3 homework in the entire quarter. The first midterm was extremely easy, and the second one was pretty fair as well. Nothing beyond what we learned in class. The final was difficult. There is one question that didn't resemble the type of question we did before, but Tang gave the hint during the exam, and this helped me. I think for this class, as long as you figure out all the fundamentals and basic stuff, an A is very doable. Even though you might get stuck on a few hard questions on the final, if you did all the other ones right, you will still get a good grade. Remember what determined your grade is not how hard this course is, but how smart your peers are. There's no need to panic when you saw a really difficult question on the exam because most of the other students probably do not know how to solve it as well.

Not a great lecturer. Writes very small on the board, skips steps when doing problems, and often uses unintuitive academic language when explaining concepts. I ended up using Paul's Notes during most of the lectures to follow what was going on. Not that the material is especially difficult, but just that it can be hard to understand what Tang says.

There were 4 HW assignments throughout the quarter, and only three were graded. They were graded for correctness, so do them carefully. Before each exam, Tang gives out a practice exam. TAKE THESE SERIOUSLY, because they closely resemble the actual exam. He lets you have a cheat sheet for each exam, so write down those problems and their solutions. The midterms were challenging but doable (90% and 60% averages); the final was quite difficult (49% average).

Overall an okay class. Don't rely on lectures for learning the material and do study the book and prepare for hard problems.

The homework is easy enough but doesn't really prepare you for the tests. The professor is obviously not a native English speaker and often misunderstood or under-explained complex questions in class.

Professor Tang is a nice guy and pretty funny at times, but he doesn't know how to teach. The lectures are really confusing, and the tests are really hard. Even the people who already took this class (AP Calc BC) in high school are confused during lecture. He likes to go on long, unnecessary proofs sometimes, and he's not the greatest at explaining concepts. My TA was way more helpful than Professor Tang.
The good thing about this class is that he curves the entire class so that the lowest possible grade you can get is a C. He curves it so that it's 30% A, 40% B, and 30% C. So it is impossible to fail this class.
You also don't need to buy the textbook, he gives you a pdf from which he will assign homework every week.

Math 31B with Prof Tang is a good option for those who have a fairly decent background in math in high school and do not really bother to retain what you learned for future uses. For me personally, I'm not a math-related major and it is the last math class I need to take in college for major prerequisites. Most of my peers in this class are probably non-math majors as I could tell from the grade distribution, so no peer pressure and trust the curve. But overall, I don't feel like Tang's way of engaging with material enables me to actually learn much from him, but as long as you follow his lectures and do practices before exams, passing the tests and getting an A is absolutely doable (with very very light workload)!

I literally made a bruinwalk profile just to set the record straight on this professor because he does NOT deserve a high rating. He is the least helpful, most ambiguous and downright the worst lecturer I’ve had at UCLA. It’s true, his tests are similar to the homework and yes it’s also true that the material for this class isn’t hard, or at least it wouldn’t be if you actually had a professor who could explain it. This class felt a lot like fumbling through a dark room, completely blind, trying to find a needle in a haystack, aka nearly impossible. Lectures were unclear and the textbook was equally unhelpful. The professor wouldn’t show up to office hours, but he was so arrogant in explaining things he probably wouldn’t have helped anyway. MANY times during lecture he would explain something with “because it is so” or “let’s move on because I think this makes sense” even if he entire class was staring blankly at the board. That being said, some people did do well in this class so maybe having a background in probability/statistics was assumed (I had none). Either way, you’ve been warned.