一、唤起经验——“起跑”《小学数学新课程标准》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。夏老师在教学《分数的意义》这一概念时,就是从学生学情出发,短短的一句“你已经知道了什么”唤起了学生已有的知识经验,找到了新知与旧知的链接点,改变了传统的概念教学“复习-引新-练习-巩固”的程式化教学。教师借助媒体教学手段向学生介绍分数的由来,适时渗透了数学文化思想。导入部分,教师对于知识结构的变革,缘于教师全新的课程理念,使学生的思维开始了“起跑”。二、文本阅读——“加速”建构主义教学论认为:学生的知识建构不是教师 First, to evoke the experience - “Start” “Primary Mathematics New Curriculum Standards” that: mathematics teaching activities must be based on the level of cognitive development of students and existing knowledge based on experience. Xia teacher in the teaching of “the meaning of the score,” the concept is starting from the student learning, a short sentence, “you already know what” aroused the students already know the experience of knowledge and found a link between the new knowledge and the old knowledge, Changed the traditional concept of teaching “review - cited new - practice - consolidation” of the program of teaching. Teachers use media teaching methods to introduce students to the origin of scores, timely infiltration of mathematical culture. In the part of introduction, teachers ’transformation of the knowledge structure is due to the teacher’s new curriculum concept, which enables the students’ thinking to start “starting.” Second, the text reading - “accelerated” Constructivism teaching theory that: the students’ knowledge is not a teacher