\input zb-basic \input zb-matheduc \iteman{ZMATH 2012d.00041} \itemau{Teng, Yanhui} \itemti{Let Weishu'' be called Wuming'' --- Further discussion on the origin and development of decimal metric system in ancient China.} \itemso{J. Liaoning Norm. Univ., Nat. Sci. 33, No. 3, 311-315 (2010).} \itemab Summary: We investigate the origin of a fractional number and the process of developing into decimal metric system in ancient China, and find the different origins in ancient China. According to ancient calendars, the extensive use of the metric system and the development of a small number are discussed. Ancient Chinese fractional number originated from the relationship of the proportion, subdivision of measurement and integer division. It has wide range applications and a set of theories on fractional number has been formatted. China has long been thinking of the decimalism. Its real meaning lies in Weishu'' being Called Wuming". But the modern sense of the metric system did not appear until the Song and Yuan Dynasties because ancient Chinese mathematics pursued high-precision on numerical algorithm. \itemrv{~} \itemcc{A30} \itemut{a fractional number; decimal system; calendar} \itemli{} \end