1. Usually, be careful not to be sloppy and do the questions carefully. Only by keeping the habit of being careful at ordinary times can we cope freely at critical times. Usually, it is almost impossible to be careless at critical moments. If you can't speak well at the same time, forget it. If you want to get good grades, you must do so.

2. When doing the problem, if it is a familiar question type, the general problem is not big, and it is most likely to make mistakes if you are unfamiliar. I don't know how to do it because it is a relatively new topic. I've tried and done it, but you're definitely not sure. Is this topic right? No bottom. In this case, there is a better way to determine whether you have done it right, and that is to do it in another way. If the result is the same, it is basically correct. If you don't have the ability to do it in other ways and are not familiar with this problem, you can only take the exam according to the original idea to see if there are any basic mistakes. The possibility of a correct result is greatly reduced.

For unfamiliar topics, you can't be sure whether you have done it right or not. This won't be solved for a while. Forget it. But for familiar topics, doing something wrong is the most regrettable thing. So we must avoid such a thing. In order to avoid this kind of thing, take a moment to make a simple rough estimate, whether the result is within the range that should be. If not, it must be wrong. Whether it is necessary is uncertain. If only there were other ways to be sure. If not, you can only carefully check whether the process is correct.

4. In order to speed up the problem, some basic constants and formulas must be memorized.

To sum up, if you keep the habit of doing problems carefully and maintain a very high accuracy, then there won't be too many mistakes. This is my own experience. Use it if you think it's useful. If you feel useless, forget it.