Editing Numeral (linguistics) (section)

===20: vigesimal===
{{Main|Vigesimal}}
Vigesimal systems are based on the number 20. Anthropologists are convinced the system originated from digit counting, as did bases five and ten, twenty being the number of human fingers and toes combined.<ref name="Heath, Thomas 2003"/><ref name="ReferenceA">Georges Ifrah, ''The Universal History of Numbers: The Modern Number System'', Random House, 2000: {{isbn|1-86046-791-1}}. 1262 pages</ref>
The system is in widespread use across the world. Some include the classical [[Mesoamerica]]n cultures, still in use today in the modern indigenous languages of their descendants, namely the [[Nahuatl]] and [[Mayan languages]] (see [[Maya numerals]]). A modern national language which uses a full vigesimal system is [[Dzongkha language|Dzongkha]] in Bhutan.

Partial vigesimal systems are found in some European languages: [[Basque language|Basque]], [[Celtic languages]], [[French language|French]] (from Celtic), [[Danish language|Danish]], and [[Georgian language|Georgian]]. In these languages the systems are vigesimal up to 99, then decimal from 100 up. That is, 140 is 'one hundred two score', not *seven score, and there is no numeral for 400 (great score).

The term ''[[20 (number)|score]]'' originates from [[tally stick]]s, and is perhaps a remnant of Celtic vigesimal counting. It was widely used to learn the pre-decimal British currency in this idiom: "a dozen pence and a [[20 (number)|score]] of [[shilling|bob]]", referring to the 20 [[British shilling coin|shilling]]s in a [[pound sterling#Pre-decimal|pound]]. For Americans the term is most known from the opening of the [[Gettysburg Address]]: ''"Four score and seven years ago our fathers..."''.