“两位数乘两位数的笔算”是苏教版教材三年级下册第四单元的教学内容。教材首先呈现的是“订牛奶”的数学问题情境,接着展现的是学生可能出现的解决问题的思维过程,呈现了不同的计算方法。教材的设计意图显而易见——倡导“算法多样化”。这样 “Double-digit by two digit pen arithmetic ” is the teaching content of the fourth unit of the third grade of the Sujiao version of textbooks. The textbook first presents the mathematical problem situation of “milk ”, followed by the students may appear to solve the problem of thinking process, showing a different calculation method. Textbook design intent is obvious - Advocacy “Diversification of Algorithms ”. such