有些习题用常规方法很难解决或不能解决,但若能把握问题的特征,通过变换思维的角度,运用假设、分解、整体把握等方法,可以使问题得以解决,这种改变思维途径,取得解题结果的方法,我们称之为等效思维。运用等效思维解题的关键是变换思考的角度,并能整体把握问题的特征。例如,对于 Some exercises can not be solved or can not be solved by conventional methods. However, if we can grasp the characteristics of the problems, we can solve the problems by changing the thinking, using the methods of hypothesis, decomposition and overall control. The result of the method, we call it equivalent thinking. The key to solve the problem by using the equivalent thinking is to change the perspective of thinking and grasp the characteristics of the problem as a whole. For example, for