【案例】教学“求相差”应用题前,我设计了这样一个教学过程:出示挂图,让学生了解图上的信息,然后提出一个数学问题,理解数量之间的关系,寻找解决问题的方法。我按照课前设计,在黑板上挂出了例题图,问:“同学们,从这张图上你得到了哪些数学信息?”学生们立刻举手:“这是花片,我 【Case】 Before the application of the teaching “Difference”, I designed such a teaching process: to produce the flip chart, let the students understand the information on the map, and then put forward a mathematical problem, understand the relationship between the quantity and find the solution to the problem. In accordance with the pre-class design, I hung out a sample diagram on the blackboard and asked: “My classmates, what mathematical information did you get from this picture?” The students immediately raised their hands: "This is a flower, I