I think, first of all, the more difficult it is to learn the later mathematics. It is very important to ensure concentration in class, independent completion of homework, a certain amount of practice, and laying a good foundation. It takes a lot of effort. What I learned in the first few years of primary school is only superficial, but only by actual study can I get good results, which is only the basis for later study. Moreover, it is not good for children to measure their current math scores with previous knowledge. What you have to do is to encourage children, analyze the reasons and communicate with teachers more.