对长、宽、高的理解通常被确定为“认识长方体”这节课的教学难点,人教版教材对于该难点突破的编排意图是:在初步了解长方体基本特征的基础上,通过小组合作用小棒和橡皮泥搭建一个长方体框架,了解12条棱之间的关系,再让学生进一步抽象概括(可以分为几组?相交于同一顶点的三条棱长度相等吗),最终得出:相交于一个顶点的三 The understanding of long, wide and high is usually identified as “knowledge of the rectangular ” This lesson difficult teaching, PEP textbooks for the difficult breakthrough layout intent is: an initial understanding of the basic characteristics of the cuboid, based on the group Cooperation with a small stick and plasticine to build a rectangular frame to understand the relationship between the 12 edges, and then let the students further abstract summary (which can be divided into several groups? Intersect at the same vertex of the three prism length equal to it), the final draw: Three intersecting at one vertex