教学内容问题化 ,教学过程探索化 ,是研究性学习在课堂教学中的两个最显著的特征 .因此 ,立足课堂 ,深入挖掘教材是研究性学习的基础 .请看高中新教材《数学》第一册 (上 )第 92页的一道练习题 :如图1,有一块边长为 a的正方形铁皮 ,将其四个角各截去一个边长为 x的小正方形 ,然 The problem of teaching content and the exploration of the teaching process are two of the most significant features of research learning in classroom teaching. Therefore, based on the classroom, digging deeper into the teaching materials is the basis of research learning. Look at the high school textbook “Mathematics” One volume (top) of an exercise question on page 92: As shown in Figure 1, there is a square iron sheet with a side length a, and each of its four corners is cut off to a small square with a side of x, then