Math doesn't need rote memorization, and there is no skill. Therefore, in the subject of mathematics, what you have to do is practice, but it is not enough to just do the problem. If you do this problem, you will know this kind of problem, otherwise you will do it in vain. You don't have to do it right, you must understand it. But doing problems will still be of great help to mathematics.

If you don't understand, you can ask questions and hope to adopt them. .