数列教学之初,经常有学生会问,这种题型为什么要用这种方法?这种方法是怎么想到的?而一些教师的回答往往缺乏说服力,甚至还有“凭经验”的回答.如等差与等比乘积型数列的求和问题,我们都知道利用“错位相减法”求解,但为什么要这样求,这种方法是如何得出的?等等,类似的问题还有很多.如何打破这一尴尬的局面?笔者提出以下几点建议,供同行参考.一、借助概念、公式的推理,先入为主等差数列与等比数列是两类特殊的数 At the beginning of the series teaching, students often ask why this type of question should be used and how did this approach come to mind? Some teachers’ answers often lack persuasion and even the “empirically” answer As with the summing of the equality and the geometric product series, we all know that using the “disjoint subtraction” solution, but why such a method is derived, and so on, a similar problem There are many .How to break this awkward situation? The author made the following suggestions for peer reference. With the help of concepts, formulas, preconceived and so on.