1, algebra and number: algebra is an important branch of mathematics, involving concepts such as variables, equations and functions. For junior high school students, mastering algebra knowledge can lay a solid foundation for subsequent study. For example, you can choose some topics about equation solving, factorization, inequality proof and so on. , so that students can better understand algebraic concepts and problem-solving methods.

2. Graphics and Geometry: Geometry is another important branch of mathematics, which involves the relationship between the shape, size and position of graphics. For junior high school students, mastering geometry knowledge can cultivate their spatial imagination and logical thinking ability. For example, you can choose some topics about triangles, quadrilaterals, circles and so on. So that students can better understand geometric concepts and problem-solving methods.

3. Probability statistics: Probability statistics is a branch of mathematics closely related to real life, involving data collection, collation, analysis and prediction. For junior high school students, mastering the knowledge of probability and statistics can help them better understand some phenomena and problems in life. For example, you can choose some topics about random events, probability calculation, statistical charts, etc., so that students can better understand the concept of probability statistics and the method of solving problems.

Junior high school mathematics learning skills:

1. Make a study plan: Make a reasonable study plan, spread the key points and difficulties to different time periods, and ensure that there is enough time to study and review math knowledge every day.

2. Actively participate in the classroom: actively participate in classroom discussion and answering questions, interact with teachers and classmates, and ask questions that teachers don't understand in time, so as to better understand and master mathematics knowledge.

3. Take notes and summarize: record important knowledge points, formulas, examples and other contents for easy reference at any time. After learning a unit or chapter, we should summarize and sort it out in time to make the knowledge systematic and organized.

4. Do more exercises: Mathematics is a subject that needs a lot of practice. By doing more exercises, we can deepen our understanding and mastery of knowledge points and improve our problem-solving ability and thinking level.