The first volume of mathematics in the fifth grade of primary school, multiples and factors are suitable for trial teaching. According to relevant data, in the first volume of mathematics in the fifth grade of primary school, the course of multiples and factors is the most difficult knowledge. It can be used to examine students' learning level of difficult knowledge points and provide targeted counseling. The first volume of mathematics in the fifth grade of primary school includes fractional multiplication, fractional division, simple equations and so on.