随着经济的发展,录音、录像、投影、幻灯等电教手段已广泛进入课堂,在教学中,恰当地运用电教手段,不仅可以激发学生的学习热情,而且可以弥补学生认识与实际生活的差距.数学本身就是一门与生活联系比较紧密的学科,不同的是,学生所要学习的知识是人类几千年来积累的间接经验,它具有较高的抽象性,要使他们理解性地接受、消化,仅凭目前课堂上教师的口耳授受是不可能的. With economic development, audio-visual methods such as audio recording, video recording, projection and slideshows have entered the classroom widely. In teaching, proper use of audio-visual means can not only stimulate students ’enthusiasm for learning, but also make up for the gap between students’ awareness and actual life. Mathematics itself is a subject closely related to life, the difference is that the knowledge that students want to learn is the indirect experience accumulated by mankind for thousands of years, it has a high degree of abstraction, so that they understandably accept, digest , It is impossible to accept and accept the teacher’s speech in the present classroom only.