在“圆的认识”教学过程中,教师应该明确,圆指的是一条封闭曲线,而不是指由封闭曲线所围成的圆面。关于这个问题,有的教师虽然自己知道圆是什么,但在教学中是不大注意讲准确的,不自觉地将圆说成是圆面。因此,不少学生,在学习了圆的概念后,头脑中留下了“圆就是由封闭曲线所围成的圆面”这个错误的认识。以致进入中学学习平面几何时分不清圆内、圆外、圆上的区别;学习解析几何时弄不懂 In the teaching of “Circle of Knowledge”, teachers should make it clear that a circle refers to a closed curve, not a circle surrounded by a closed curve. On this issue, some teachers, although they themselves know what a circle is, do not pay much attention to teaching in an accurate and unconscious circle. Therefore, many students, after studying the concept of a circle, have left the wrong understanding that “a circle is a circle formed by a closed curve”. So as to enter the middle school geometry can not distinguish between round, round, round the difference; learn to understand geometry do not understand