我以往讲“圆锥体体积”一课时,常常自己演示让学生看,或是自己演示后再让一两个学生演示,以证实圆锥体体积是与它等底等高圆柱体体积的1/3,其效果都不理想。学生作业中不是忘记“乘以1/3”,就是对“等底等高”这一先决条件意识淡薄。为了解决这个问题,我再次讲这一内容时,课上做了改进,加强了学生自己实践的环节,效果比较理想。 首先我将全班学生分为四个小组,每组给定准 When I used to talk about “cone volume”, I often showed myself to students for demonstration or to have one or two students demonstrate after demonstrating themselves to confirm that the cone volume is 1/3 of the volume of the cylinder with the same height , Its effect is not ideal. Students do not forget the “multiplied by 1/3” operation, that is, the precondition of “waiting for the end contour” is weak. In order to solve this problem, when I say this again, the classes have been improved and the students' practice of their own has been strengthened. The result is quite satisfactory. First I divided the class into four groups, each given a quasi