It doesn't matter. Primary school mathematics is the foundation of junior high school mathematics, so it is not too difficult for primary schools to learn junior high school well. The focus of primary school mathematics is to lay a good foundation of mathematics. So its content is mainly about numbers, the relationship between numbers and numbers. Various quantities and measurement methods. Various basic operations and basic quantitative relations. Basic graphic understanding and simple calculation of perimeter, area and volume. And simple algebraic knowledge.

What's the difference between junior high school mathematics and primary school mathematics?

Junior high school mathematics focuses on cultivating students' mathematical ability, including calculation ability, self-study ability, ability to analyze and solve problems, abstract logical thinking ability and so on. Complex knowledge of plane geometry is added to the content, algebra knowledge is systematically studied, and practical problems are solved by equations; Number is extended to rational number and real number. There are simple linear functions and quadratic functions.

The fundamental difference between primary school and middle school is that primary school pays attention to results and conclusions, while junior high school pays attention to the process of reasoning, namely proof and geometry.