为什么只看一个自然数的个位就可以确定它是否是2和5的倍数?进行分数加减法,为什么只把分子相加减,分母不能相加减?为什么分母中不含有2和5以外的质因数的最简分数才能化成有限小数?小朋友,你想过这些问题吗?当你把这些问题真正想明白的时候,你的思维会变得更深刻,你的数学学习会变得更 Why only look at a natural number of units can determine whether it is a multiple of 2 and 5? The fractional addition and subtraction, why only add and subtract the numerator, the denominator can not be added and subtracted? Why the denominator does not contain 2 and 5 Children, have you ever thought of these questions? When you really want to understand these questions, your thinking will become more profound and your math learning will become more