Editing Numerical digit (section)

==History of ancient numbers==
{{Main|History of writing ancient numbers}}
Counting aids, especially the use of body parts (counting on fingers), were certainly used in prehistoric times as today. There are many variations. Besides counting ten fingers, some cultures have counted knuckles, the space between fingers, and toes as well as fingers. The [[Oksapmin]] culture of New Guinea uses a system of 27 upper body locations to represent numbers.<ref>{{Cite book|author=Saxe, Geoffrey B.|title=Cultural development of mathematical ideas : Papua New Guinea studies|date=2012|publisher=Cambridge University Press|others=Esmonde, Indigo.|isbn=978-1-139-55157-1|location=Cambridge|pages=44–45|quote=The Okspamin body system includes 27 body parts...|oclc=811060760}}</ref>

To preserve numerical information, [[Tally marks|tallies]] carved in wood, bone, and stone have been used since prehistoric times.<ref>{{Cite book|author=Tuniz, C. (Claudio)|title=Humans : an unauthorized biography|others=Tiberi Vipraio, Patrizia, Haydock, Juliet|date=24 May 2016|isbn=978-3-319-31021-3|location=Switzerland|pages=101|oclc=951076018|quote=...even notches cut into sticks made out of wood, bone or other materials dating back 30,000 years (often referred to as "notched tallies").}}</ref> Stone age cultures, including ancient [[Indigenous peoples of the Americas|indigenous American]] groups, used tallies for gambling, personal services, and trade-goods.

A method of preserving numeric information in clay was invented by the [[Sumer]]ians between 8000 and 3500&nbsp;BC.<ref>{{Cite book|author=Ifrah, Georges|title=From one to zero : a universal history of numbers|date=1985|publisher=Viking|isbn=0-670-37395-8|location=New York|pages=154|oclc=11237558|quote=And so, by the beginning of the third millennium B.C., the Sumerians and Elamites had adopted the practice of recording numerical information on small, usually rectangular clay tablets }}</ref> This was done with small clay tokens of various shapes that were strung like beads on a string. Beginning about 3500&nbsp;BC, clay tokens were gradually replaced by number signs impressed with a round stylus at different angles in clay tablets (originally containers for tokens) which were then baked. About 3100&nbsp;&nbsp;BC, written numbers were dissociated from the things being counted and became abstract numerals.

Between 2700 and 2000 BC, in Sumer, the round stylus was gradually replaced by a reed stylus that was used to press wedge-shaped cuneiform signs in clay. These cuneiform number signs resembled the round number signs they replaced and retained the additive [[sign-value notation]] of the round number signs. These systems gradually converged on a common [[sexagesimal]] number system; this was a place-value system consisting of only two impressed marks, the vertical wedge and the chevron, which could also represent fractions.<ref>{{Cite book|url=https://books.google.com/books?id=qxP0yJa2G6oC&q=he+vertical+wedge+and+the+chevron&pg=PA226|title=London Encyclopædia, Or, Universal Dictionary of Science, Art, Literature, and Practical Mechanics: Comprising a Popular View of the Present State of Knowledge; Illustrated by Numerous Engravings and Appropriate Diagrams|date=1845|publisher=T. Tegg|pages=226|language=en}}</ref> This sexagesimal number system was fully developed at the beginning of the Old Babylonia period (about 1950&nbsp;BC) and became standard in Babylonia.<ref>{{Cite book|last=Neugebauer|first=O.|url=https://books.google.com/books?id=v1bmBwAAQBAJ&q=sexagesimal+number+system+was+fully+developed+at+the+beginning+of+the+Old+Babylonia+period|title=Astronomy and History Selected Essays|date=2013-11-11|publisher=Springer Science & Business Media|isbn=978-1-4612-5559-8|language=en}}</ref>

[[Sexagesimal]] numerals were a [[mixed radix]] system that retained the alternating base&nbsp;10 and base&nbsp;6 in a sequence of cuneiform vertical wedges and chevrons. By 1950&nbsp;BC, this was a [[positional notation]] system. Sexagesimal numerals came to be widely used in commerce, but were also used in astronomical and other calculations. This system was exported from Babylonia and used throughout Mesopotamia, and by every Mediterranean nation that used standard Babylonian units of measure and counting, including the Greeks, Romans and Egyptians. Babylonian-style sexagesimal numeration is still used in modern societies to measure [[time]] (minutes per hour) and [[angle]]s (degrees).<ref>{{Cite book|chapter=Sexagesimal System|place=Berlin/Heidelberg|publisher=Springer-Verlag|doi=10.1007/978-1-4020-4425-0_9055 |title=Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures |date=2008 |last1=Powell |first1=Marvin A. |pages=1998–1999 |isbn=978-1-4020-4559-2 }}</ref>