最近听了一节“变与不变”的数学活动课,其中有这样一个操作活动:每生一块圆柱形橡皮泥,任意捏搓把它变成别的形状。学生的积极性非常高,但刚过一分钟,教师就要求同桌互说各自捏成的泥什么变了,什么不变。交流中,学生说出泥的总量不变,但只是重复说变粗、变细,没有其他的话可说,教师却在一旁不时地称赞XX真行、XX真棒。整堂课看上去应 Recently heard a “change and changeless” math class, which has such an operating activities: a piece of cylindrical plasticine per student, any pinch twist it into another shape. The enthusiasm of the students is very high, but just after a minute, the teacher asked the same table each said what their mud has changed, what does not change. During the exchange, students said the total amount of mud unchanged, but only repeated that thicker, thinner, there is nothing else to say, teachers are from time to time praised XX Zhenxing, XX awesome. The whole class should look like