There are algebra, geometry, function, and the most difficult thing is function. Algebra and geometry are based on functions. You can find all the math books, then do the following exercises and read the books from beginning to end. What matters is the foundation of junior high school and primary school. If the foundation of junior high school is not good, it will be difficult for senior high school and technical secondary school. If it is based on anything, it should be your arithmetic ability. Tell you a way to improve your math ability. Reciting numbers is very effective. Hope to be adopted, it is all from experience.