.magnetic whiteboard erasers.In mathematics classroom teaching, sometimes a large amount of blackboard content is needed. In the 40 (or 45) minutes of the class, if the traditional blackboard book is still used, it will consume valuable time in the class. If it is not written, it will often inaccurate words. At this time, if the courseware is played in the electronic whiteboard, not only can the problem of a large number of blackboards in the classroom be solved, but also the classroom teaching capacity can be greatly increased, and the classroom time can be used efficiently. For example, when learning "application of linear programming", classroom teaching needs to supplement extracurricular examples, and at the same time supplement some classroom exercises. The content of the blackboard is very difficult and difficult. After using multimedia technology as a display tool, it can be avoided in the classroom. Write a large number of books, save a lot of time and increase the classroom teaching capacity. Based on interactive whiteboard