一、直观演示操作形成表象阶段从第一册准备课开始“认识图形(一)”,先后出现大小不一、相互位置关系变化的长方形、正方形、三角形、圆形等平面几何图形的直观认识,接着在第二册“认识图形(二)”中又出现了长方体、正方体、圆柱体、球等立体实物与图形的直观认识。教材内容安排上,先出现大小、位置关系变化而不改变其本质 First, the visual presentation of the operation to form the image of the stage From the first book preparatory class “understanding of the figure (A)”, has appeared in different sizes, the mutual changes in the relationship between rectangular, square, triangle, circular geometric plane intuitive understanding, Then in the second volume of “understanding of the figure (b)” appeared in cuboids, cubes, cylinders, balls and other physical objects and graphics intuitive understanding. Textbook content arrangements, the first appearance of size, location changes without changing its essence