任何圆锥体积都是圆柱体积的1/3吗?在对这个问题进行判断时,经常有部分学生会作出肯定的回答。他们对此问题判断错误的原因,是由于对“等底、等高的圆锥和圆柱体积的比较”这一大前提模糊不清而造成的。为了使学生对上述问题(包括一些变式题)能作出正确的判断,我在教学中加强圆柱体与圆锥体相互关系的教学,通过引导学生动手操作,突出“等底等高”这一关键特征,使学生切实掌握圆锥体体积计算公式V=(1/3)sh。在新授课时,我将全班分为四个小组,每组都给定准备好的实验器材:圆柱、圆锥和砂子,然后提出问题:“把圆锥里装满砂往圆柱里装,直至装满为止,你们能发现什么?”同学们边 Any cone volume is 1/3 of the cylinder volume? In judging this issue, often some students will make a positive answer. The reason for their misjudgment of this issue is the result of the ambiguity of the general premise of “comparison of the volumes of cones and cylinders at the end of an equinox.” In order to enable students to make correct judgments on the above issues (including some variant questions), I strengthened the teaching of the relationship between cylinder and cone in teaching. By guiding students to operate hands and highlighting the key of “equal contour” Characteristics, so that students can effectively grasp the cone volume calculation formula V = (1/3) sh. In my new class, I divided the class into four groups, each given a set of experimental equipment: cylinders, cones, and sand, then asked the question: “Fill the cone with sand in a cylinder until it fits What can you discover when you are full? ”