【片断一】出示例题,引导分析。师:这道题和以前求面积问题不一样了,这道题能直接求吗?面积发生了什么变化?生:面积增加了。师:面积怎么增加的?生:长增加了3米,面积就增加了18平方米。师:长增加了,面积就一定增加吗?我可不相信,你有办法让我相信吗?光看文字,我也看 [A piece] to produce examples, guide analysis. Teacher: This question is different from the previous question of asking for an area. Can this question be directly asked? What has changed in area? Health: The area has increased. Teacher: How to increase the area of ​​Health: Health increased by 3 meters, the area increased by 18 square meters. Teacher: If the length increases, will the area increase? I do not believe, can you believe me? Look at the text, I also read