基于《数学课程标准》(实验稿)的七年级(上)数学教材中,都包含了由小正方体组成的几何体的三视图的认识和画法的内容,是学习其他几何体三视图的基础.由于对三视图的理解、认识不够,没有弄清楚其意义,部分学生对其画法存在一定的困难.要弄清其意义,应先从长方体的长、宽、高的认识开始,首先弄清楚其长、宽、高各有多少个单位长度.认识长方体(如图1所示): The seventh grade (top) math textbook based on the “Mathematics Curriculum Standard” (experimental version) contains the content of the three views of the geometry composed of small cubes and is the basis for learning the other three views of the geometry. Understanding of the three views, understanding is not enough, did not find out its significance, some students have some difficulties in their painting method.To find out its meaning, we should first learn from the cuboid length, width and height, the first to clarify its Length, width, height, how many units of length. Understanding cuboid (as shown in Figure 1):