建模点1:“图形的周长”模型所属内容:信息窗1(第83页—85页)教材简析:图形的周长是“图形与几何”领域的重要内容之一,是学生已经初步认识了长方形、正方形、三角形和圆形的基础上进行教学的。周长作为一维空间概念,它必须依附于二维的平面而存在。如何借助学生已有的生活经验和知识水平,帮助学生从二维的平面上抽象并在头脑中建立“一周的长度就是周长”的表象认识,是周长意义教 Modeling Point 1: “Perimeter of the Shape ” Model Belonging Content: Information Window 1 (pp. 83-85) Textbook Analysis: The perimeter of the graphic is one of the important areas in the “Graphics and Geometry” , Is that students have initially learned to teach on the basis of rectangles, squares, triangles and circles. Perimeter as a one-dimensional space concept, it must be attached to the two-dimensional plane and exist. How to use the existing life experience and knowledge level of students to help students abstract from the two-dimensional plane and establish in their minds. “The length of a week is the perimeter”, and the perimeter sense