It takes 2 ~3 weeks to finish reading all the blocks in the high school mathematics textbook, including 1 day, function 5 days, solid geometry 4 days, analytic geometry 5 days, vector 2 days, combination arrangement 2 days and probability 2 days. Look on the bright side of knowledge. Look at one piece at a time, and you'd better choose a few questions with moderate difficulty to do after-school exercises. If you know them, go through them.

Of course, it's best to find a high school math teacher (multiple rounds) to explain what you don't understand. After all, high school mathematics can't be learned in a day. If a teacher gives you an on-demand program, you can get twice the result with half the effort

Of course, you should have perseverance, because you have to finish learning mathematics in such a period of time. Mathematics is very boring, and it can only be mastered by understanding. Many technical terms need to be memorized, and many theorems and inferences need to be understood. You can find some test questions to do.

You'd better have a high school math outline and review it according to the outline.