Yan Tan Tethera
English and Scottish shepherds used a special numeral system for counting sheep, derived from a Celtic language.
Different number systems for different contexts occurs in other languages as well. For example, in some Phillipine languages, there are native numerals into the thousands which are used in regular discourse, but in the context of money and time, Spanish numbers are used.
And while we’re on the topic of number systems, the Danish system is always fun, because everyone trips on it. It’s partially vigesimal, that is, base-20. Sixty is tres, short for tresindstyve, that is, 3 times 20. But halvtreds (short for halvtredsindstyve, half three times twenty) isn’t 30, it’s 50. Seventy is halvfjerds (half four score), eighty is firs (firsindstyve, four score), and ninety is halvfems (half five score); but a hundred is hundrede, not fems. And fyrretyve, which sounds like it’s four times twenty (tyve), is actually forty, from fyritiughu. So there are three counterintuitive concepts at play here: one, a base-20 number system. Two, the notion that half-X means halfway between X and the number that precedes it. Hence, halvannen is 1.5, that is, half the second, and halvtreds is 50, that is, half the third score. Thirdly, a sound change made the word for forty sound like four times the word for twenty.
French, too, has a remnant of a vigesimal system. Ten is dix and twenty is vingt. Eighty is quatre-vingts, i.e., four times twenty, and ninety is quatre-vingt-dix, or four times twenty plus ten.
I’m on a roll today: did you know that across languages, numerals for five are often the same or related to the word for hand, while the word for ten may be a compound related to “two hands”? In languages of Papua New Guinea, the word for twenty is often a compound meaning “one person” — a person usually has ten fingers and ten toes, which makes twenty. (This and the anecdote about languages of the Phillipines come from this book.)
