【概述】数学是一门逻辑性,系统性很强的学科,前面知识的学习,往往是后面有关知识的基础,新旧知识的联系是非常紧密的。“颠倒相乘”是分数除法教学中常用的方法,运算起来比较容易,但学生在很长时间里都无法理解。我尝试采用“通分法”算法来揭示知识间的内在联系,以使学生在以有知识的基础上进行知识间迁移,以 【Overview】 Mathematics is a logical and systematic subject. The learning of the previous knowledge is often the basis for the later knowledge, and the relationship between the old and the new knowledge is very close. “Multiplying ” is a commonly used method of teaching fractional division, which is easier to calculate, but students can not understand for a long time. I try to use “common method ” algorithm to reveal the intrinsic linkages between knowledge so that students can transfer knowledge based on knowledge