“一口清”是珠心算乘除运算的基础 ,其基本方法是“本个加后进”。因此 ,如何让学生熟记 ,掌握本个律和进位律 ,是“一口清”教学的重点。笔者根据小学低年级学生的特点 ,主要是采用分步教学的方法。第一步 :本个律的教学本个律的教学比较简单 ,主要采用类似乘法口诀背诵的方? “Clear” is the basis of abacus multiplication and division operation, the basic method is “this plus plus.” Therefore, how to enable students to memorize and grasp the law and the law of subordination is the key point of “paying lip service”. According to the characteristics of the lower primary school students, the main method is to use step-by-step teaching. The first step: the teaching of this law The teaching of the law is relatively simple, the main method used to recite a similar multiplication formulas?