通过观察,我发现老师用普通的教学圆规在黑板上画圆时,不好固定圆心,而且不好把握所画圆的半径的大小。因此,我发明了“带刻度尺的吸盘圆规”。一、我的发明要解决的问题我的发明要解决现有普通教学圆规的以下4个缺点:1.圆规只能做画圆工具; Through observation, I found that when the teacher draws a circle on a blackboard using an ordinary teaching compass, it is not good to fix the center of the circle, and it is not good enough to grasp the size of the radius of the circle drawn. So, I invented the “sucker compass with scale”. First, the problem to be solved by my invention My invention to solve the following four shortcomings of the existing general teaching compasses: 1 compasses can only do circular painting tools;