在一次全国性的小学数学教学研讨会上,有幸聆听了一位优秀青年教师(甲)与一位特级教师(乙)关于六年级“认识比”的同课异构教学。两位老师结合自身的教学功底和特色,展现出了各自独特的教学风采。这两堂课让笔者感受到数学课堂教学研究的两种不同流派与风格,久久回荡于脑际。对比之余,颇受启发。一、同课异构教例片段呈现针对“认识比”一课中关于同类量比的意义建构,两位老师在引入和建构环节中分别展开了如下教学过程: At a national seminar on primary school mathematics teaching, I was fortunate to hear the teaching of one excellent young teacher (A) and one super teacher (B) on the same course in sixth grade “understanding ratio ”. Two teachers with their own teaching skills and characteristics, demonstrated their unique teaching style. These two classes let the author feel two different genres and styles of mathematics classroom teaching and research, long echoed in the brain. In contrast, quite inspired. First, the lesson of heterogeneous teaching in the same lesson presents the construction of the meaning about the same kind of ratio in the class of “cognition ratio”, the two teachers respectively carry out the following teaching process in the introduction and construction: