采用“退一加补”熔进“破十法”的方法教学“20以内退位减法”,学生思路清晰,计算迅速,事半功倍。下面以“13—6”为例,谈谈具体做法: 一、用学具帮助理解计算每个学生拿出自制学具板(如图)数一数每排有几格?共有几排?让学生放13个圆片在格子里,每个格子只放一个,要求能一眼看出总个数。 Adopt the method of “refusing one plus adding” and melting into “breaking ten methods” to teach “less than 20 absenteeism subtraction”, the students have clear thinking, rapid calculation and multiplier. The following to “13-6”, for example, to talk about the specific approach: First, the use of learning tools to help understand the calculation Each student come up with the number of self-made learning board (Figure) Students put 13 discs in the grid, put one in each grid, asked to be able to see the total number.