It is clearly pointed out in the mathematics curriculum standard: "The development of modern information technology has had a great influence on the value, goal, content and the way of learning and teaching of mathematics education. The design and implementation of mathematics curriculum should attach importance to the application of modern information technology. " Indeed, in the information age, multimedia technology has played its unique role in classroom teaching. It can create realistic teaching environment, alternate teaching images, adjust classroom atmosphere and give teaching feedback in time. Fully mobilizing students' enthusiasm for exploring new knowledge and keeping them in a state of excitement, pleasure and knowledge-seeking can not only effectively avoid learning-weariness, reduce students' excessive learning burden, but also greatly improve classroom teaching efficiency. It has become a prerequisite for this kind of learning. Bruner, an American psychologist, said: "The best stimulus for learning is interest in learning materials." According to the principle of situational teaching, create as real a situation as possible related to the teaching theme, so that students can get concrete feelings about the objective situation, stimulate their desire for learning, actively engage in the exploration of knowledge, and give full play to their potential ability, thus generating interest in learning and broadening their horizons. For example,