数学课程标准指出:“数学教学活动必须建立在学生的认知发展水平和已有的知识经验基础之上”.“教师应激发学生的学习积极性,向学生提供充分从事数学活动的机会,帮助他们在自主探索和合作交流的过程中真正理解与掌握基本的数学基础知识与技能、数学思想方法,获得广泛的数学活动 The mathematics curriculum standard states: “Mathematics teaching activities must be based on the students ’level of cognitive development and existing knowledge and experience.” "Teachers should stimulate students’ enthusiasm for learning by providing students with the opportunity to fully engage in math activities to help them In the process of independent exploration and cooperation and communication, we should really understand and master basic basic knowledge and skills in mathematics, mathematical thinking and methods, and acquire a wide range of mathematical activities