【教材分析】教材结合乘法分配律的教学,在学生已经了解和掌握乘法分配律的基础上,安排了应用乘法分配律进行简便计算的教学。在例题教学中,教材的设计做到了“收放自如”。“放”体现在例题结合学生熟悉的超市购物的问题情境,引导学生列出算式,教学时先让学生自己尝试计算,并呈现学生可能出现的三种算法。而这三种算法本质上又是一致的,这就为学生深刻理解乘法分配律,感受运用乘法分配律进行简便计算的方法提供了极为丰富的素 【Textbook Analysis】 teaching materials combined with the law of multiplication distribution law, students already know and grasp the multiplicative distribution law, based on the arrangement of multiplication distribution law to facilitate the calculation of teaching. In the example teaching, the design of teaching materials has done “free and easy ”. “Put ” is reflected in the example of the problem the students familiar with the supermarket shopping situation, guide students to formulate formulas, teaching students to try to calculate their own, and presents the students may appear three algorithms. These three kinds of algorithms are essentially the same, which provides students with a profound understanding of the law of multiplicative assignments and provides a very rich method for using simple multiplication assignments