Decimal: Difference between revisions

Starting from the 2nd century BC, some Chinese units for length were based on divisions into ten; by the 3rd century AD, these metrological units were used to express decimal fractions of lengths, non-positionally.<ref name=jnfractn1>{{Cite book | author=Joseph Needham | author-link=Joseph Needham | chapter = 19.2 Decimals, Metrology, and the Handling of Large Numbers |pages=82–90 | title = Science and Civilisation in China |volume=III, "Mathematics and the Sciences of the Heavens and the Earth" | title-link=Science and Civilisation in China | year = 1959 | publisher = Cambridge University Press}}</ref> The 5th century mathematician [[Zu Chongzhi]] calculated a 7-digit [[approximations of π|approximation of {{mvar|π}}]]. Calculations with decimal fractions of lengths were [[Rod calculus#Decimal fraction|performed using positional counting rods]], as described in the 3rd–5th century ''[[Sunzi Suanjing]]''. The 5th century mathematician [[Zu Chongzhi]] calculated a 7-digit [[approximations of π|approximation of {{mvar|π}}]]. [[Qin Jiushao]]'s book ''[[Mathematical Treatise in Nine Sections]]'' (1247) explicitly writes a decimal fraction representing a number rather than a measurement, using counting rods.<ref>Jean-Claude Martzloff, A History of Chinese Mathematics, Springer 1997 {{isbn|3-540-33782-2}}</ref> The number 0.96644 was denoted