老师说:“如果牧羊人把20只羊放到牧场上去吃草,有5只羊跳出了围栏,还会剩下多少只?”小麦克大声回答说:“一只都没有。”老师说:“我很惊讶,你竟然不会算数。我知道你的算术很好的,现在竟会出错。”小麦克说:“老师,你懂算术,但你不了解羊。我知道,若是有一只羊跳了出去,其余的就会跟着她跳出去。” The teacher said: “If the shepherds put 20 sheep grazing in the pasture, 5 sheep out of the fence, but also how many?” Small Mike replied loudly: “None at all. ” “The teacher said:” I was surprised that you would not have counted. I know your arithmetic is good and now I am going wrong. “” Mike said: “Teacher, you know arithmetic, but you do not know sheep. I know that if a sheep jump out, the rest will follow her out. ”