Professor Do posts very detailed lecture notes, but he was one of the few math profs who actually motivated me to attend lectures because he presents things in a pretty intuitive and easy-to-follow way. His exams are very fair - he might throw in a slightly tricky question or two, but usually offers generous EC (we're talking ~7 points on a 100-point exam) to make up for it. His exams often draw directly from homework assignments, which can take a while, but they're worth doing and he's very willing to help you out (or straight up give you the answer) during office hours. 10/10 would take again

If you need to take Math 115A, take it with Prof. Do! His lectures and notes are very clear and his subtle jokes made the class engaging despite that it was at 9am. His homeworks are long but are very useful since similar problems are used on tests. The exams are fair as they mostly have similar problem types to those covered in class, though a few problems are designed to be “curveballs.” Whenever a problem is too hard, he gives everyone extra points on the tests. Also, he is very helpful during office hours and helps you to significantly improve your proofs. I would totally recommend this class with Prof. Do!