Compasses can only be used in the sixth grade of primary school. Compass is a tool for drawing circles or strings in mathematics and drawing, and is often used for drawing with a ruler.

Compasses are made of metal and plastic, including two parts connected by hinges, which can be adjusted. Primary school is a school where people receive primary formal education and an important part of basic education.

The compass also has an extension rod and a chalk leg. When people want to draw a big circle, but the original two rods are not long enough, it is enough to connect the extension rod. When people want to draw a chalk line circle, they change it to a chalk line foot.