《数学课程标准指出》:“义务教育阶段的数学课堂,其基本出发点是促进学生全面持续、和谐地发展”.为此数学教学既要考虑数学自身的特点,更应遵循学生学习数学的规律,注重从学生已有的知识和生活经验出发,让学生亲身经历数学建构的过程.这种主动建构必须是学生对已有知识和经验进行体验、反思的基础上实现的.从而使学生获得对数学理解的同时,在认知、情感、能力等多方面得到发展.一、大胆猜想,激活思维现代教学论认为,在课堂教学中,学生的学习是两个转化过程,一是由教材的知识结构向学 “The mathematics curriculum standard states:” The basic starting point of compulsory education is to promote the students ’continuous and harmonious development. "Therefore, mathematics teaching should not only consider the characteristics of mathematics itself, but also follow the students’ learning mathematics Law, focusing on students’ existing knowledge and life experience, allowing students to experience the process of mathematical construction.This initiative must be constructed on the basis of experience and reflection of existing knowledge and experience, so that students can obtain Understanding of mathematics at the same time, in the cognitive, emotional, ability and other aspects of development.And bold guess, activate the thinking Modern teaching theory that in the classroom teaching, student learning is two transformation process, one by the textbook Knowledge structure to learn