Junior high school is mainly algebra and plane geometry. Algebra includes application problems, factorization, equations and so on. Personally, I think factorization is the most basic. You can simplify the equation or the formula in high school mathematics in the future. Plane geometry is mainly parallel lines and parallelograms. Triangle, similar triangles, circle. Parallel lines and the like are relatively simple, while triangles and circles are more difficult in junior high school geometry. The moving point problem that often appears in the senior high school entrance examination needs the geometric knowledge of circles and triangles to solve.

Senior high school mathematics should start with the sequence of numbers, followed by trigonometric function, analytic geometry, derivative, permutation and combination. I think sequence is the most difficult, analytic geometry is the most troublesome, and permutation and combination are the most interesting. Geometry is mainly solid geometry. There is a lot of content. This is just a summary. Suggest finding a website. Mathematics is different from Chinese. You can see your grades if you work hard.