一、问题缘起1.不可回避的尴尬:练得越多,错得越多一次,在我校数学单元考试卷上有一题(要求是能简算的要简算):720÷18+720÷12,结果有不少学生做成“=720÷(18+12)=720÷30=24”。而这道题是不能简算的,应该按照运算顺序计算,即“=40+60=100”。细想来,学生是把乘法分配律的运算负迁移到了这道题的解决上。不少有经验的教师会发现,平常对于乘法分配 First, the problem origins 1. Unavoidable embarrassment: practice more, the more the wrong time, in my school math exam papers have a question (the requirement is to be simple to calculate): 720 ÷ 18 + 720 ÷ 12, the result is a lot of students made “= 720 ÷ (18 + 12) = 720 ÷ 30 = 24 ”. And this question is not simple, it should be calculated according to the order of operations, that is, “= 40 +60 = 100 ”. Carefully come, the student is the operation of multiplication assignment negative transfer to solve the problem. Many experienced teachers will find that the usual distribution for multiplication