In fact, I have also taken those students who have a good foundation and can't get high marks. There are roughly the following reasons.

1. Non-intellectual factors lose points, simple questions are easy to lose points, and difficult problems are often careful.

I am confident and like mental arithmetic.

3. Look at the missing keywords, there are none, not necessarily, or the conditions are wrong.

4. Walk into the small trap set by the teacher.

The most important thing is that I am usually good at math, so I spend more time on other subjects, less math practice, less problem solving and lack of experience in solving problems. As a result, you can't finish the questions in the fastest, best and simplest way, and you don't have enough time and your score is not high.