Because math problems are changeable, different kinds of math problems have different methods to solve them. A lot of questions are not done, just like many words in English are not memorized. Once you encounter problems that you haven't encountered before in the exam, it's hard to solve (high IQ can be ignored).

Of course, we can't just ask questions about sea tactics. When you do the problem, you should draw inferences from one instance to another. The highest state of doing a problem is that doing a problem will produce a kind of problem. Don't do repetitive, too simple or too difficult questions. It is very slow and wastes a lot of time.