I haven't learned the previous things, so I have to make up now. I have experience in this field. It is said that I didn't complete the whole course in the second year of high school for some reason, and finally got more than 80 points in the college entrance examination ... Anyway, you need to do the following:

1. Recite the concept, recite all the mathematical concepts, and you will find that your understanding of the concept is much deeper.

2. Rewrite the original exercises-not written in a notebook (usually written in a book, which is not difficult enough to turn over), but the exercises set by the teacher-summarize all the questions clearly.

While doing the above two points well, try to find some questions to do. It doesn't need much, but you must do a few questions every day.

That's all. I hope it helps you.