1, understanding of numbers and formulas: understanding of numbers, understanding of rational numbers, understanding of algebraic expressions, square difference formulas and other basic concepts and knowledge.
2. Set and function: the understanding of set, the relationship between sets, the concept of function, linear function, and the preliminary grasp of inverse proportional function.
3. Graphics and transformation: understanding of points, lines, planes and bodies, concept of angles, similarity and congruence of graphics, translation, rotation, folding, similarity transformation and so on.
4. Mathematical reasoning and application: mathematical induction, mathematical expression, square deformation, making statistical chart, understanding of simple probability, etc.