There are the following differences between junior high school mathematics and primary school mathematics: 1. Abstraction and logic increase: Compared with primary school mathematics, junior high school mathematics pays more attention to the development of abstraction and logic. In junior high school mathematics, students will learn more algebra, geometry and function knowledge, which requires abstract thinking and reasoning. At the same time, students need to start using logical proof methods. 2. Transition from written calculation to algorithm: Primary school mathematics focuses on cultivating students' computing foundation and basic computing ability, and emphasizes the methods and skills of written calculation. In junior high school mathematics, students began to learn more arithmetic rules, such as four operations of integers, fractions and decimals, and began to use calculators, paying attention to the rules and principles of operations. 3. Strengthen problem-solving ability: Junior high school mathematics focuses on cultivating students' problem-solving ability. Students will exercise their analytical, reasoning and problem-solving abilities by establishing mathematical models and solving practical problems. Junior high school mathematics pays more attention to cultivating students' mathematical thinking and creativity. 4. Systematization and depth increase of mathematics knowledge: Compared with the sporadic knowledge points of primary school mathematics, the knowledge system of junior high school mathematics is more complete and systematic. Students will learn more mathematical concepts, principles and theorems, and need to establish a more perfect mathematical knowledge system. At the same time, the depth and difficulty of mathematics will gradually increase, which requires students to understand and master it more deeply. 5. Introduction of abstract questions and proofs: In junior high school mathematics, students will begin to contact some abstract questions and proofs. For example, students will begin to learn to solve equations and prove geometric theorems, and they need to use logic and reasoning to solve problems and prove them. In a word, junior high school mathematics pays more attention to the cultivation of abstract thinking, logical reasoning and problem-solving ability than primary school mathematics. It not only extends the breadth and depth of mathematical knowledge, but also introduces abstract questions and proofs. Through the study of junior high school mathematics, students will better grasp the basic concepts and methods of mathematics and lay a solid foundation for further study of senior high school mathematics.