《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和掌握基本的数学知识与技能、数学思想和方法,获得广泛的数 The Mathematics Curriculum Standard states that mathematics teaching activities must be based on the students’ level of cognitive development and existing knowledge and experience. Teachers should stimulate their enthusiasm for learning and provide students with opportunities to fully engage in math activities so as to help them to understand and master basic math knowledge and skills, mathematical ideas and methods in their own exploration and cooperation and exchange, and obtain a wide range of numbers