The mathematics ability of primary school students generally refers to the ability of calculation, preliminary logical thinking, preliminary spatial concept and the ability to solve simple practical problems by using what they have learned. Knowledge is the foundation of ability, and all kinds of mathematical abilities are gradually formed and developed in the process of learning mathematical knowledge. At the same time, the mastery of knowledge is restricted by ability, and ability determines the degree of real mastery. The two complement each other and influence each other.

Second, the principle of combining theory with practice.

The universality of application is one of the three characteristics of mathematics. Linking mathematics teaching with real life, emphasizing sources and uses, so that students can feel that there is mathematics everywhere in their lives. Mathematics is a science that can be seen, touched and used. This can stimulate students' interest in learning, help them master the basic knowledge of mathematics, improve their ability to analyze and solve simple practical problems, and cultivate their awareness of mathematics application.

Third, the principle of combining concreteness with abstraction.

Lenin pointed out that people's understanding is from intuitive images to abstract thinking, and from abstract thinking to practice, which is a dialectical method of understanding truth and objective practice. Mathematics is a very abstract subject. To solve the contradiction between the high abstraction of mathematics and the concrete visualization of primary school students' thinking, it is important to adopt intuitive teaching.

Fourth, the principle of combining rigor with acceptability.

Stiffness is a major feature of mathematics, and the certainty of conclusions comes from the rigor of logic. Acceptability depends on students, that is, all the teaching contents should conform to the physical and mental development level of primary school students, step by step, with moderate difficulty and easy for students to accept. In mathematics teaching, we should not only pay attention to the rigor of mathematics itself, but also conform to the acceptance ability of primary school students. Only by combining them closely can we effectively promote students to master mathematical knowledge and improve their mathematical ability.