在“平行四边形面积”的教学中,一位老师为了突出平行四边形面积公式是由长方形转化而来,在巩固练习时,每一道题都不忘问学生:这个平行四边形其实可以看做什么图形?这个平行四边形的底和高分别相当于长方形的什么?直到学生都会说“平行四边形可以转化成长方形”时,老师才感到“心满意足”。可是,第二天练习课中学生对 In the teaching of “Parallelogram Area”, a teacher transformed the rectangular parallelepipedal area into a rectangle. In consolidating the practice, each question did not forget to ask the students: What can be considered as a parallelogram? What does the shape and shape of the parallelogram mean at the bottom of the rectangle correspond to the rectangle? The teacher feels “satisfied” until the student says “the parallelogram can be converted into a rectangle.” However, the next day middle school students practice