Classroom practice is an important part of classroom teaching, an indispensable link in students' learning process, and an important means for students to master knowledge, form skills and develop intelligence. Through students' classroom exercises, teachers can understand students' mastery of knowledge, so as to adjust teaching contents and teaching measures in time. Therefore, the design of classroom exercises directly affects the effectiveness of students' mathematics learning. In teaching practice, some teachers don't like to include exercises in preparing lessons. They simply think that exercises are students' homework. As soon as the new class is over, they will give it to the students. What they are most concerned about is the correct rate of practice. If the correct rate is not high, they will talk and the students will do it again. Some teachers have considered some problems in practice, but seldom pay attention to whether the content, type and level of practice are rich or not. Later, when students encounter problems in practice, teachers will talk about them, which increases the burden on teachers and students and virtually discourages students' enthusiasm for learning mathematics. How do our primary school math teachers improve the effectiveness of classroom exercises in teaching? I think we can consider the following points. First, clear objectives, so that every classroom exercise has a clear purpose, try to avoid multiple purposes at the same time, which will inevitably lead to mutual interference, and so will students.