(1) Take math notes, especially the different aspects of concept understanding and mathematical laws, as well as the extra-curricular knowledge expanded by teachers in class. Write down the most valuable thinking methods or examples in this chapter, as well as your unsolved problems, so as to make up for them in the future. (2) Establish a mathematical error correction book. Write down error-prone knowledge or reasoning in case it happens again. Strive to find wrong mistakes, analyze them, correct them and prevent them. Understanding: being able to deeply understand the right things from the opposite side; Guo Shuo can get to the root of the error, so as to prescribe the right medicine; Answer questions completely and reason strictly. (3) memorize some mathematical laws and small conclusions, so that your usual operating skills can reach the proficiency of automation or semi-automation. (4) Regularly organize the knowledge structure, form a plate structure, and implement "overall assembly", such as tabulation, to make the knowledge structure clear at a glance; Often classify exercises, from a case to a class, from a class to multiple classes, from multiple classes to unity; Several kinds of problems boil down to the same knowledge method.