在数学解题中,为完成论证,求值、化简等任务,常要对某些式子进行恒等变形,但恒等变形又无一定之规,一个式子往往有多种可能的变形方向,因题而异,技巧性非常强.本文介绍两种常用的恒等变形技巧——“加0”与“乘1”.在解题中适当地运用这两种变形技巧,可化繁为简、化难为易,能产生“山重水复、柳暗花明”的效果,从而达到事半功倍. In mathematics problem solving, in order to complete the argumentation, evaluation, simplifying and other tasks, it is often necessary to carry out the equal deformation of certain formulas, but there is no certain rule for constant deformation, and one formula often has many possible deformation directions. Due to the differences in the questions, the skills are very strong. This article describes two commonly used equal-distortion techniques - “plus 0” and “multiply by 1.” In the problem-solving appropriate use of these two deformation techniques can be simplified It is difficult to change, and it can produce the effect of “heavy hills, heavy hills, and dark mountains”, so as to achieve a multiplier effect.