First of all, we must adjust our mentality! Adapt to the teacher, not wait for the teacher to adapt! Preview before class and concentrate on class! Do a few more questions after class to consolidate! If you don't understand, you must ask! Similarly, I have changed many teachers, and now I am a senior three, and I am always changing … so this is my experience! Moreover, high school is a self-study process, and you can't always rely on teachers! You can do a good preview; Ask your classmates and teachers after class. In addition, you can buy a problem solution of the same grade, but it is not used to copy homework, but to imitate it, and then slowly keep up with the teacher and improve your math level. If you don't understand in math class, you should try to ask your classmates or teachers in your spare time until you understand, so that you won't say that you don't understand at all in the next math class, and you should learn with an open mind!