《义务教育数学课程标准》指出:学生的数学学习内容的选择要贴近学生的实际,有利于学生体验、思考与探索。学生学习应当是一个生动活泼的、主动的和富有个性的过程,动手实践、自主探索与合作交流是学习数学的重要方式,学生应当有足够的时间和空间经历观察、实验、猜测、验证、推理、计算、证明等活动过程。 “Compulsory education mathematics curriculum standards” pointed out: The choice of students ’mathematical learning content should be close to the students’ actual conditions, which is good for the students to experience, think and explore. Student learning should be a lively, active and individualized process. Hands-on practice, self-exploration and cooperation and exchange are important ways to learn mathematics. Students should have enough time and space to observe, experiment, guess, verify and reason , Calculation, certification and other activities process.