Reviews of professor He Zhang

Rating: 2.0/5, difficulty: 5.0/5
Instructor Zhang is a terrible professor. The homework has nothing to do with what is on the exams. The only reason I gave him a 2 instead of a 1 is because he is very accessible outside of class and outside of his office hours.

Rating: 5.0/5, difficulty: 4.0/5
Professor Zhang knows his stuff, and he is very accessible outside of class for help. If you ask a question he will be sure to answer it as thoroughly as possible. This is a tough class and the material is difficult but the practice exams help a lot so be sure to do them.

Rating: 5.0/5, difficulty: 3.0/5
He is a good lecturer and the notes he provides to his students are really good. The notes are super helpful and clear. His lectures can be a bit difficult to understand sometimes, but 9 out of 10 times I leave classes knowing what is going on. He is super accessible outside of class and wants to help you do well. He has been great for online 251.

Rating: 2.0/5, difficulty: 2.0/5
Having 5 exams within a semester might be stretching it, but since they aren't cumulative they end up being fairly easy. HW and Sample Exams provide about every type of question that could be asked, so the whole thing is a breeze. That being said, lectures are extremely boring, dry, and he frequently stopped to fix typos on the notes, so not great

Rating: 5.0/5, difficulty: 3.0/5
Definitely take him for Math 251. No doubts. His lectures are clear, and notes that he provides are well organized. Takes care of the students a lot, and he gives a lot of feedback if you ask for it. Again, just take him if you get a chance to join his class.

Rating: 3.0/5, difficulty: 3.0/5
This is a challenging course, and Professor Zhang does his best. The exams are written by the course administrator. With that said, he provides sample exams that are VERY similar to the exams. He is always willing to give extra help and answers his email very quickly. I always email him asking for feedback on the hw and he is happy to help.