数学课堂拓展环节的教学,可以使数学学习内容由课内向纵深处或向课外延伸。可以是主体内容的辐射、铺垫和延续,也可以是某一知识点的综合、深化和提高。有效的教学拓展,能使趋于平静的课堂再起波澜,一方面使本课的教学内容得到升华和总结,另一方面为学生的后继学习埋下伏笔,做好铺垫,从而优化教学效果。许多教师深谙此理,非常重视课堂教学的拓 The teaching of the expansion of math class can make the contents of math learning extend from the class to the depth or to the class. Can be the main content of the radiation, bedding and continuity, but also can be a comprehensive knowledge of the point, deepen and improve. Effective teaching and development, can calm the classroom again waves, on the one hand so that the contents of this lesson to be sublimated and summed up, on the other hand, lay the foundation for students’ successors to study, so as to pave the way to optimize teaching effectiveness. Many teachers are familiar with this theory, attaches great importance to the extension of classroom teaching