Pay attention to find out where the child's problem is, and solve the problem before the child's grades can go up. Junior high school mathematics is relatively simple, and few children are simply stupid and can't get up. First, give the child a basic knowledge test, which can be in the form of a question and answer. At the same time, you can get a general understanding of your child's mastery, your child's learning initiative, whether you have missed classes before, whether you have studied hard at ordinary times, whether you are careless, and so on. When giving lectures, we should grasp the basic knowledge and questions, remember the basic knowledge accurately, read more questions, and the grades will naturally go up. For children who can't extrapolate, try to guide them to think. For children who are not confident, we can start with some simple basic questions. Encourage children in time when they are right, enhance their self-confidence and make them love learning. A child who is often careless can urge him to form the habit of checking, and if necessary, he can do some pure calculation problems and tell him to punish him three times for one mistake until he is right.