本课设计由长方形旋转得到圆柱体,由直角三角形旋转得到圆锥体,其用意一方面让学生获得科学的有关圆锥体的概念,另一方面让学生进行空间感知,培养学生的空间观念。对于学生的猜想,均给予鼓励,因为虽然这些“猜想”的结果不一定正确,但就“猜想”本身而言是合理的,而创新的智慧火花往往在“猜想”的瞬间被点燃,同时,种种不同猜想结果又激发起学生进行验证的需要。 This class is designed to rotate the rectangle from a rectangle to a cone. The purpose of this lesson is to give students a scientific conception about cones. On the other hand, students can learn the space and cultivate the students’ concepts of space. The students’ conjecture is encouraged because although the results of these “guesses ” may not be correct, “conjecture ” itself is reasonable, and the spark of innovation is often in “conjecture ” Instantly lit, at the same time, the results of a variety of different guesswork inspired students need to verify.