1. Junior high school mathematics faces the senior high school entrance examination three years later, while primary school mathematics does not face such an exam.

As we all know, the math test questions in the senior high school entrance examination not only examine the basic knowledge, but also pay attention to the students' ability, so there are many difficulties in the test questions. The focus of primary school questions is to examine basic knowledge. Primary school mathematics focuses on laying a good mathematical foundation, while junior high school mathematics focuses on cultivating students' mathematical ability, including calculation ability, self-study ability, problem analysis and problem solving ability, abstract logical thinking ability and so on.

2. Junior high school mathematics knowledge increases, learning time is short, and the speed is fast.

Learn some basic knowledge of mathematics in primary school for six years, and six books in junior high school for three years. In fact, you have to study for two and a half years, so you have to squeeze out half a year to review the senior high school entrance examination. Junior high school mathematics has added complex knowledge of plane geometry, systematically studied algebra knowledge and solved practical problems by using equations; Number is extended to rational number and real number; There are simple linear functions and quadratic functions. The learning content of junior high school mathematics has increased and deepened, and the difficulty and requirements have increased.