As a traditional Chinese calculation tool and an important ancient Chinese invention,the abacus was widely used before the invention of Arabic numerals in the world. The abacus is a rectangle with a wooden frame. Within the frame,rods with stringed beads are fixed. The beam in the middle of the frame divides each rod into two parts. The two counting beads in the upper part of each rod represent five and the rest five beads in the lower part represent one. With the application of the abacus, people summarized many calculation tips to help improve the speed of calculation. As the abacus is simple to produce, and its calculation tips are easy to memorize and operate, it is quite popular in China.