问:为什么要学习近似数? 答:这主要有两方面的原因,一方面是在生活、生产实际问题中把一个数搞得完全准确有时是办不到的,比如课本的长和宽,很难量出它们丝毫无差的准确长度;另一方面,不加分析地把每一个数都弄得一清二楚有时也没有必要.比如一个人的年龄是多少,完全没必要精确到月日. Q: Why do we have to learn approximate numbers? Answer: There are two main reasons for this. On the one hand, it is not possible to accurately count a number in practical problems in life and production. For example, the length and width of textbooks are very different. Difficult to measure their exact length without any difference; on the other hand, it is not necessary to make every number clear without analysis. For example, what is the age of a person is absolutely not necessary to be accurate to the date of the month.