The word "abacus calculation" first appeared in the Han dynasty mathematician Xu Yue's "Records of Mathematics", only ten words "abacus calculation, control belt four hours, longitude and latitude three only", according to the northern Zhou mathematician Zhen Luan notes: "the three points, the upper and lower two points, to stop swimming beads, the middle one point, to determine the calculation position. Each five beads, the upper bead and the lower four beads color. The beads of different colors on it should be five, and the four beads under it should be one each. To the bottom of the four beads, so the cloud control belt four. Its beads swim in the three parties, so the cloud: longitude and latitude are also three." It can be seen from zhen Luan's notes that the word "abacus" describes the predecessor of the modern abacus -- the abacus plate or abacus board. Chinese and foreign abacus according to the really difficult ah notes have given the swim abacus disk or abacus board to the map, and according to the push to the left of the physical model. Comparatively representative, such as Yu Chiang, Li Peiye, Xu Chunfang, etc., put forward their own deductive plans and models.