一、说教材长方体的认识是在学生以前初步认识了一些简单的立体图形（长方体、正方体、圆柱和球等）和一些平面图形的特征以及它们的周长和面积的计算，形成了一定的空间观念的基础上进行学习的。教材在编写时注意培养学生实际操作能力。通过实际观察。制作、测量、拆拼等活动 First, the teaching material Cuboid understanding is that before the students a preliminary understanding of some simple three-dimensional graphics (cuboids, cuboids, cylinders and balls, etc.) and some of the characteristics of planar graphics and their perimeter and area calculations, forming a certain space The concept of learning based on. Teaching materials in the preparation of students to pay attention to the actual operation ability. Through the actual observation. Production, measurement, dismantling and other activities