乘法分配律是一种重要的数学模型,由于它不同于乘法交换律与乘法结合律等较为单一的运算,因此在小学阶段所学的运算律中,它是学生最难理解和掌握的。有些学生在学习时就糊里糊涂,始终弄不明白乘法分配律为什么会有这种形式上的变化;有些学生虽然在学习时会机械地模仿,但很快就遗忘了,更谈不上自觉和灵活地运用……所以在教学中我们不能 Multiplicative distribution law is an important mathematical model, because it is different from the multiplication law and multiplication law and other relatively simple arithmetic, so in the elementary school arithmetic law, it is the most difficult for students to understand and grasp. Some students are confused when they are studying. They still can not understand why the law of multiplication and division has such formal changes. Although some students will imitate mechanically while learning, they soon forget, let alone consciously And flexible to use ... So in teaching we can not