初中代数、几何都是从研究简单数式、简单图形开始的 ,而复杂数式、复杂图形的问题都是通过转化、归结为简单数式、简单图形来获得解决的 .这种在对问题作细致观察的基础上 ,借助旧知识、旧经验来处理新问题的思想 ,我们称之为“化归思想” .本文从思维的角度 ,重点介绍纵向、 Junior algebra and geometry are all started from the study of simple numbers and simple graphs. The problems of complex numbers and complex graphs are solved through transformation and reduction to simple numbers and simple graphs. This is a detailed observation of the problems. On the basis of the idea of ​​dealing with new problems with the help of old knowledge and old experience, we call this “return to the idea.” This article focuses on portraits from the perspective of thinking.