《数学课程标准》指出:数学教学活动必须建立在学生认知水平和已有的知识经验基础之上,学生的数学学习活动是在教师组织、引导下的自我建构、自我生成的过程。因此,学生的学习活动不是由教师向学生传递知识,而是由学生根据外在信息,通过自己的背景知识,建构自己知识体系的过程。在这个过程中,外部信息以学生自己原有的知识经验为基础 The mathematics curriculum standard points out that the mathematics teaching activities must be based on the cognition level of the students and the existing knowledge and experience. The students ’mathematics learning activities are the process of self-construction and self-generation under the guidance of teachers’ organizations. Therefore, the student’s learning activity is not the teacher to pass the knowledge to students, but by students based on external information, through their own background knowledge, the process of building their own knowledge system. In this process, external information is based on the student’s own prior knowledge of the experience