在教学“折线统计图”这节课之前,笔者对该课进行了深入的分析,在教学设计时力图帮助学生解决两个疑惑。一是让学生明白当认识了条形统计图后,为什么还要学习折线统计图。二是为什么书上说:条形统计图方便我们看出各种数量的多少,折线统计图能够比较清楚地表示出数量增减变化的情况,这怎么解释呢? In the teaching “polyline chart ” before this lesson, I conducted an in-depth analysis of the lesson, trying to help students solve two puzzles in the teaching design. First, let students understand that when you know the bar chart, why you still want to learn the line chart. The second is why the book said: bar chart convenient for us to see how much of the number, line chart can be more clearly expressed changes in the number of changes, how to explain it?