帮助学生建立明晰的数学概念,是学生掌握基础知识与基本技能的先决条件。例如:要使学生真正掌握整数、小数和分数加减法的法则,首先要使他们建立“计数单位相同”这一概念。只有这样,才能使学生真正懂得整数加减为什么要相同数位对齐;小数加减为什么要小数点对齐; Helping students to develop clear mathematical concepts is a prerequisite for students to acquire basic knowledge and basic skills. For example, to enable students to really grasp the law of integers, decimals and fractional additions and subtractions, first they should be allowed to establish the concept of “identical counting units.” The only way to enable students to truly understand why integer addition and subtraction to the same digit alignment; decimal addition and subtraction why the decimal point alignment;