Like most Celtic numbering systems, they tend to be vigesimal ( score ( e . g . 5 score sheep = 100 sheep ).
22.
What caused the irregularities in the French system so that, despite the rest of the system being decimal, 70-99 are vigesimal?
23.
:: Yes, the French vigesimal system is attributed to the Celtic substrate, for which see also the sheep counting system yan tan tethera.
24.
Another piece of evidence for the Vasconic language, according to Vennemann, is the persistence of vigesimal ( base-20 counting ) traits in Danish.
25.
The Long Count 0.0 . 1.0 . 0 represents 360 days, rather than the 400 in a purely base-20 ( vigesimal ) count.
26.
The " numeral " system was originally purely vigesimal and went up to 400, but a decimal system was introduced for numerals above 100 via Russian influence.
27.
This reform arose after the French Revolution to unify the different counting systems ( mostly vigesimal near the coast, because of Celtic ( via Breton ) and Viking influences ).
28.
The Maya civilization and other civilizations of pre-Columbian Mesoamerica used base-20 ( vigesimal ), as did several North American tribes ( two being in southern California ).
29.
Early number systems that included positional notation were not decimal, including the sexagesimal ( base 60 ) system for Babylonian numerals and the vigesimal ( base 20 ) system that defined Maya numerals.
30.
The Mesoamerican Long Count calendar developed in south-central Mexico and Central America required the use of zero as a place-holder within its vigesimal ( base-20 ) positional numeral system.
