1, make students realize the close relationship between mathematics and real life, and realize that numbers and symbols are important languages to describe the quantitative relationship in the real world.

2. Promote students' interest and self-confidence in learning mathematics, and cultivate students' initial innovative consciousness and discovery ability.

3. Cultivate students to understand the real world from a scientific perspective.

4. "Number and algebra" is the basis of mathematical knowledge system.

Algebra is a branch of mathematics, which studies the general solutions and properties of numbers, quantities, relationships, structures and algebraic equations (groups). Elementary algebra is generally taught in middle schools, introducing the basic ideas of algebra: studying what happens when we add or multiply numbers, understanding the concept of variables and how to establish polynomials and find their roots. The research object of algebra is not only numbers, but various abstract structures. Among them, we only care about various relationships and their nature, but we don't care about the question "what is the number itself". The common types of algebraic structures are groups, rings, fields, modules, linear spaces and so on.