“乘法分配律”是五年制小学数学第七册第一单元的内容。它是数学的一个基本定律，不仅在小学数学基础知识中占有重要地位，而且也是今后继续学习数学的基石，因此是教学的重点。由于乘法分配律对小学四年级的学生来说，较之乘法交换律与结合律抽象，所以它又是教学的难点。 鉴 The Law of Multiplication and Distribution is the content of the first unit of the seventh volume of the five-year primary school mathematics. It is a basic law of mathematics. It not only plays an important role in the elementary knowledge of mathematics in elementary schools, but also is the cornerstone of mathematics learning in the future. Therefore, it is the focus of teaching. Because the multiplication assignment law is more difficult for students in the fourth grade of elementary school than the law of multiplicative exchange and the law of combination, it is also a difficult teaching point. Kam