1.徒手画的必要性 教几何需画图,教代数也常需画图。 开始讲几何,为培养学生作图和识图的能力,需按作图基本程序用尺规进行规范作图,为学生示范,这是必要的。随着课程内容的深入,课堂上要画的图增多,如每节课45分钟内要完成十个图形,每个图形需1—2分钟,则将有半数时间用于作图,就会使 1. Necessity of Freehand Drawing geometry requires drawing, and teaching algebra often requires drawing. Beginning to talk about geometry, in order to develop students’ ability to draw and read maps, it is necessary to use the rulers to perform standard drawing according to the basic procedures for drawing. This is necessary for student demonstration. As the content of the course goes deeper, there are more drawings to be drawn in class. For example, if you want to complete 10 figures in 45 minutes in each lesson, and each figure takes 1-2 minutes, half of the time will be used for drawing.