在一节习题课上,学生对一个问题(本文“问题Ⅲ”)提出了老师备课时未考虑到的一种解法.对此,老师随机应变,利用学生的解法因势利导地做了一点“文章”.这样,便使问题Ⅲ的解答走了一段“弯路”.然而,这段弯路却引发了学生浓厚的学习兴趣.本节课原来的安排是,先由师生一起探讨三 In an exercise class, students put forward a solution to a problem (“Problem III” in this article) that teachers did not take into account when preparing lessons, in which case the teacher made a “case study” based on the circumstances and using the student’s solution. In this way, the solution to Problem Ⅲ takes a “detour.” However, this detour has given rise to a strong interest in learning. The original arrangement in this lesson was to first discuss with teachers and students the three