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c. 2800 BC — Indus Valley civilization on the Indian subcontinent, earliest use of decimal ratios in a uniform system of ancient weights and measures, the smallest unit of measurement used is 1.704 millimetres and the smallest unit of mass used is 28 grams. [citation needed]
counting rod decimal fraction 1/7. Starting from the 2nd century BCE, some Chinese units for length were based on divisions into ten; by the 3rd century CE these metrological units were used to express decimal fractions of lengths, non-positionally. [28]
1698 (perhaps deriving from a much earlier use of middle dot to separate juxtaposed numbers) division slash (a.k.a. solidus ) 1718 (deriving from horizontal fraction bar, invented by Abu Bakr al-Hassar in the 12th century)
260 BC – Greece, Archimedes proved that the value of π lies between 3 + 1/7 (approx. 3.1429) and 3 + 10/71 (approx. 3.1408), that the area of a circle was equal to π multiplied by the square of the radius of the circle and that the area enclosed by a parabola and a straight line is 4/3 multiplied by the area of a triangle with equal base ...
Before the establishment of the decimal metric system in France during the French Revolution in the late 18th century, [2] many units of length were based on parts of the human body. [3] [4] The Nippur cubit was one of the oldest known units of length. The oldest known metal standard for length corresponds to this Sumerian unit and dates from ...
[8]: 2–3 Although certain standards, such as the pied du roi (the King's foot) had a degree of pre-eminence and were used by scientists, many traders chose to use their own measuring devices, giving scope for fraud and hindering commerce and industry. [19] These variations were promoted by local vested interests, but hindered trade and taxation.
Sexagesimal numerals were a mixed radix system that retained the alternating bases of 10 and 6 that characterized tokens, numerical impressions, and proto-cuneiform numerical signs. Sexagesimal numerals were used in commerce, as well as for astronomical and other calculations.
Of particular note is the use in Chinese mathematics of a decimal positional notation system, the so-called "rod numerals" in which distinct ciphers were used for numbers between 1 and 10, and additional ciphers for powers of ten. [108]