《圆的认识》是苏教版数学五年级下册的内容,大部分教师在课的导入时,会从学生的已有知识经验入手,出示长方形、平行四边形、圆等图形让学生从中找到不同,从而初步感知圆的特征;抑或从圆的定长特征入手,让学生排成一个圆,在生活情境中开始探究圆。前段时间,有幸听到一节《圆的认识》,课的导入部分从点到线,由线到面,让学生在极限想象中认识动态的圆。同时这个设计一箭双雕,首尾呼应,课的结尾处更是用它帮助诠释了圆 The understanding of the circle is the content of the second grade of the fifth grade of the Sujiao version. Most teachers start with the students’ existing knowledge in the course of class introduction, and show the students the different shapes such as rectangle, parallelogram and circle , So as to initially perceive the characteristics of the circle; or start from the characteristics of the fixed length of the circle, let the students form a circle, in the context of life began to explore the circle. Some time ago, had the honor to hear a “round understanding”, the import part of the class from point to line, by the line to the surface, so that students in the ultimate imagination to understand the dynamic circle. At the same time this design double-edged sword, end to end echo, the end of the class is to use it to help explain the circle