《数学教学》1983年第6期发表了《数学教学中的“进”与“退”》一文,读后很受启发.联想到在解题中还碰到过这样的命题,利用已知数学知识一步步“进”的方法和“退中求进”的方法都不能凑效、或者非常麻烦,但如果把题目推广到一般情形,通过对一般性问题的思考,会立刻令人顿开茅塞,相当快地找到问题的解答. “Mathematics Teaching” published in the 6th issue of 1983, “Into the ” and “ Back ” in mathematics teaching. After reading it, I was inspired. Associated with such a proposition in solving problems, The step-by-step approach to using known knowledge of mathematics and the method of “retreating from the middle” are neither effective nor very cumbersome. However, if the topic is extended to the general situation, it will be through thinking about general issues. , it will immediately cause a drowning and find the solution to the problem fairly quickly.