Vigesimal numeration is a numeral system in which all derived units are based on the number 20 and the powers of 20. Vigesimal is derived from Latin word vicesimus (twentieth), based on viginti (twenty) that itself descended from a Sanskrit word, vimsatih (twenty). Other related words are vicennial (once every 20 years) and vicenary that has the same meaning as vigesimal. The use of 20 as a grouping (or base) number was used by many cultures throughout our human history (most likely) because people have twenty digits, or the number of fingers and toes.

The Aztecs and Mayans used a base 20 number system as did almost all Eskimo tribes, some native North American societies, almost all peoples native to Central and South America, and some cultures in northern Siberia and Africa. Mayan mathematics brought about the most sophisticated counting system ever developed in the Americas. Mayan numerical systems originated in...