体积概念的建立标志着学生的认识已由二维空间拓展到三维空间，这个认识转变的关键是建立起空间观念。为解决这一教学难点，我在体积概念的教学中设计了以下教学程序。一、摸一摸，直观感受空间让学生把课桌抽屉内的书包拿出来，用手在空抽屉里摸一摸，把文具盆放进去，用... The establishment of the concept of volume indicates that students' cognition has been expanded from two-dimensional space to three-dimensional space. The key to this change of understanding is to establish the concept of space. To solve this teaching difficulty, I designed the following teaching procedure in the teaching of volume concept. First, touch, intuitive feel space for students to draw the bag inside the desk drawer, touch the empty drawer in hand, put the stationery pot into it, with ...