whiteboard ghosting.In the classroom where the electronic whiteboard is applied, the teacher can use the writing pen equipped with the electronic whiteboard to operate the computer on the whiteboard at the edge of the whiteboard, and can also freely write with the pen, directly using the eraser, and arbitrarily altering. Easily implement functions such as writing on a whiteboard, marking on an electronic document, and remotely operating a computer on a whiteboard, and removing the constraints of the mouse on the action of the teacher. At the same time, students can easily learn to use the writing pen to make interaction in teaching. The teacher can also freely annotate any picture projected onto the whiteboard, and use the writing pen to realize the seamless writing and drawing on the whiteboard. The writing pen can arbitrarily select the color, adjust the thickness and transparency, and do not need a ruler, a triangle, a compass, etc. The tool makes it easy to draw beautiful graphics. If we put it into our ordinary teaching facilities in the past, we need to prepare a large number of tools to do this. The preparation work is complicated and consumes a lot of space called the ??three-foot platform??. This function of the electronic whiteboard is a major improvement to the traditional blackboard + chalk teaching mode, and it is easy to realize the mainstream means of modern teaching.