《简易方程》这一单元的内容包括用字母表示数、简易方程和列方程解应用题三部分。用字母表示数可以简明地表达数量关系的一般规律。学生以前学习的是一些具体的数及其运算,现在要从具体的数过渡到用字母表示数,对于小学生来说这是个难点。为了帮助学生突破这个难点,教材从学生热悉的知识出发,循序渐进、由浅入深地分三个层次进行讲解。第 “Simple equation” This unit includes the use of alphanumerical, simple equations and column equations solution to the problem of three parts. The number of letters can be simple to express the general rule of the quantitative relationship. Students have previously learned a few specific numbers and their operations. Now it is difficult for primary school students to make transition from concrete numbers to alphanumeric characters. In order to help students to break through this difficult point, the textbook starts from the students' hot news and proceeds step by step. It will be explained in three levels. No.