面积和周长的比较是五年制小学数学第五册第六单元第三小节的教学内容。它是继长方形和正方形面积计算之后的又一知识扩展，具有承前启后的作用，教学好这部分知识尤为重要：第一，能排除周长“负迁移”对学生思维的干扰，把学生“三混淆”的错误消灭在萌芽状态；第二，把新知 The comparison of area and circumference is the teaching content of the third bar of the sixth unit of the fifth year of elementary school mathematics. It is another extension of the knowledge after the calculation of the area of ​​the rectangle and the square, which plays an important role in teaching and learning. This part of teaching is especially important: First, it can eliminate the interference of the “negative transfer” of the perimeter to students' thinking, "The error is eliminated in the bud; second, the new knowledge