1, number one is the basic course of primary school mathematics, which mainly includes basic operations such as number recognition, number size comparison, addition, subtraction, multiplication and division. Suitable for students in the lower grades of primary school.

2. The number two is an advanced course of primary school mathematics, which mainly includes fractions, decimals, percentages, areas, perimeters, etc. Suitable for senior pupils.

3. The number three is the basic course of junior high school mathematics, mainly including algebra, geometry, functions, equations, etc., which is suitable for junior high school students to learn.