小学数学第三册简介（续）人民教育出版社数学室陶雪鹤第五单元角和直角六年制义务教材第三册第五单元主要教学角和直角的初步认识。这部分内容与现行教材相比，主要有以下一些改进：１．改变了编排顺序。现行教材对于几何知识采取集中编排的原则，把一些有联系的几何知识... Elementary Mathematics Volume 3 Introduction (Continued) People's Education Press Room Mathematics Department Tao Xuehe fifth unit angle and right angle six-year compulsory education textbook third unit fifth unit main teaching angle and angle of the initial understanding. Compared with the current teaching material, this part mainly includes the following improvements: 1. Changed the arrangement order. The current teaching material for the geometric knowledge of the principle of centralized arrangement, the number of linked geometric knowledge ...