【激趣导入】同学们,你们知道现在是什么季节吗?秋天是收获的季节,金黄色的树叶飘落,多美呀!老师采集了一些漂亮的树叶,想来欣赏一下吗?(课件演示)好看吗?有两只小蚂蚁也被漂亮的树叶吸引过来,围着树叶爬行、玩耍。它们两个想进行一场爬树叶比赛,谁能先爬完树叶的一圈谁就获胜,咱们来当裁判好不好,预备——开始。现在哪位小裁判来宣布一下比赛结果?你同意吗?为什么?(预设):红蚂蚁爬的树叶大,一圈长,比赛不公平。 [Excitement import] students, you know what season is it? Fall is the harvest season, the golden leaves falling, beautiful! Teacher collected some beautiful leaves, want to enjoy it? (Courseware demo) Good looking There are two small ants are also attracted to the beautiful leaves, crawling around the leaves, play. The two of them want to make a tree-climbing game, who can win the first round of leaves, let’s be the referee, prepare - start. Which small referee now to announce the results of the competition? Do you agree? Why? (Default): Red ants crawling leaves large, long laps, the game unfair.