Following on from a previous post on the relative complexity of counting systems in different languages, it struck me as interesting to explore a couple of the more interesting number systems in certain languages.
Starting in relatively familiar territory, French compares very similarly with English, up until a point. Whereas we name our multiples of ten using the base number and adding “-ty” (e.g. sixty, seventy, eighty, etc.). French does the same, until 70, which is soixante-dix, literally “sixty-ten”. 80 gets even stranger – quatre-vingts, literally “four-twenties”, and 90 is quatre-vingts-dix, “four-twenties-ten”.
Why the switch? Well, the upper numbers were thanks to North Germanic influence, first appearing from Normandy in northern France. The Normans picked up the vigesimal system (counting in groups of 20) from the Vikings. Given that lower numbers were much more frequently used and thus much more resistant to change, the original decimal system stuck for those. In Old French there is still evidence of the vigesimal system: treis vingts and cinq vingts, “three-” and “four-twenties”.
A similar English is also apparent in Old English (also due to Viking influence) – when counting was often done in “scores”. There are only vestigial remnants floating around in modern English, generally only recognizable in historical contexts, such as in the iconic opening to the Gettysburg address: “Four score and seven years ago”.
The only language that uses entirely base 20 for numbers is Basque.