Take up two classes. The fifth chapter of the eighth grade of mathematics published by Beijing Normal University takes two class hours, the first class hour. Mainly to let students review the basic concepts of fractions and several rules used in fractional operation, master the operational rules of fractions skillfully, and gradually get familiar with the basic skills of fractional operation through spiral understanding, so as to cultivate students' algebraic expression ability. Through the teaching of this class, students can have a deeper understanding of fractional operation.