袁隆平院士曾说:“我最喜欢外语、地理、化学,最不喜欢数学,因为在学正负数的时候,我搞不清为什么负负得正,就去问老师,老师说:‘你记住就是’.学几何时对一个定理有疑义去问,还是一样的回答.我由此得出结论:数学不讲道理,于是不再理会,学数学兴趣一直不大,成绩不好.”从他这段话中可以看出,我们在讲解有理数运算法则的引入时,如果不讲原因,甚至只简 Academician Yuan Longping once said, “I like foreign languages, geography, and chemistry most. I don’t like mathematics the most, because when I’m learning positive and negative numbers, I can’t figure out why I’m doing well. I’ll ask the teacher. The teacher said, ’You remember That is to say, “When learning geometry, there is doubt about a theorem, or the same answer. I have thus concluded that mathematics is not reasonable, so I no longer pay attention to it. I have never had much interest in mathematics and I have not achieved good results.” It can be seen from this passage that when we explain the introduction of rational arithmetic, if we don’t talk about reasons, we can only