You can go to the bookstore to look at the math materials. You should not only look at them, but also use your brain to think about the answers. Just skip them and see your weaknesses. After that, you can prepare draft paper for calculation. In class, the teacher's key points are recorded in a notebook or a special notebook, so you can have a look before the exam. Read more textbooks in your spare time and think at the same time. It took a long time to pass the exam once, but you don't have to look it up later. The so-called "go through it" means to finish one question and check it again, then check it again, and then do the next question.

This is my suggestion, I hope it will help you.