Expansion of knowledge content: junior high school mathematics involves more knowledge content than primary school mathematics. Junior high school mathematics includes geometry, algebra, function, probability statistics and so on, while primary school mathematics mainly focuses on basic knowledge such as integers, fractions, decimals and geometry.
Cultivation of abstract thinking ability: junior high school mathematics pays attention to cultivating students' abstract thinking ability. Compared with the intuitive problems and calculations in primary school mathematics, algebra and symbolic representation are introduced into junior high school mathematics, which requires students to think and reason more abstractly.
Changes in calculation methods: In junior high school mathematics, calculation methods are gradually developing in a more abstract and flexible direction. For example, primary school mathematics mainly uses vertical calculation method, while junior high school mathematics introduces more algebraic calculation and equation solving.
Cultivation of problem-solving ability: Junior high school mathematics pays more attention to cultivating students' problem-solving ability. Students need to learn to analyze and refine the mathematical characteristics of problems and use the mathematical knowledge and methods they have learned to solve problems.
Introduction of reasoning proof: Junior high school mathematics begins to introduce some simple reasoning proofs to cultivate students' logical thinking and proof ability. This is different from the characteristics of primary school mathematics, which focuses on calculation and application.
It should be noted that these differences are not absolute, and different textbooks and teaching methods may have some differences. In addition, learning mathematics is not only to master knowledge, but also to cultivate the ability to understand, apply and solve problems.