摘要
小学里，我们学习了自然数、零和分数，初中我们又学习了负数．这些数统称为有理数．你想过没有。有理数是怎么产生的？
In primary school, we have learned natural number, zero and fraction. In junior high school, we continue to learn negative number. All these kinds of number make up of a new kind of number named ＂rational number＂. Have you ever considered how rational number came into being？
