Personally, it depends on whether your basic skills are solid or not. If you get good grades, have a good foundation in mathematics, are good at summing up knowledge in mathematics and have strong self-study ability, you can buy a math review guide book from Chen Wendeng (difficult, but absolutely beneficial) or Li Yongle (focusing on basic methods) and teach yourself. This advantage is that you can follow your own procedures. If you sign up for the remedial class, your review plan will be completely disrupted. At that time, my postgraduate entrance examination was to review Chen Wendeng's books by myself and put them on.
If the foundation is not good, then sign up for a remedial class and follow the class. You must do the questions you should do. Sign up for a basic class and an intensive class, but I am very tired. One class is a whole day, and the weather is still hot!
I hope I can help you!