Base ten feels inevitable. It is not — it is anatomical. Humans have ten fingers, so most languages count in tens, and the ones that do something else usually reflect a different body-part strategy or an inherited mathematical tradition.
Base twenty is widespread
| Language | Evidence |
|---|---|
| French | quatre-vingts — four twenties for 80 |
| Danish | halvtreds — half-third twenties for 50 |
| Basque | berrogei — two twenties for 40 |
| Welsh | traditional deugain — two twenties |
| Georgian | ორმოცი ormotsi — two forties |
| Maya | fully vigesimal system |
Counting fingers and toes gives twenty, and several languages make the link explicit — in some Mayan and West African languages the word for twenty derives from a phrase meaning "one whole person".
English kept a trace in score: "fourscore and seven years ago" is 87, and the word survives only in that fossilised construction.
Danish is the most arithmetically demanding. Halvtreds abbreviates "half-third times twenty" — that is, two and a half twenties, or 50. Halvfjerds (70) is three and a half twenties. The system is opaque enough that Danish numbers are a recognised difficulty for Norwegian and Swedish speakers, who use plain decimal forms.
Base twelve leaves traces too
| Evidence | Where |
|---|---|
| eleven, twelve | not "one-teen, two-teen" — separate words |
| 12 inches in a foot | imperial measurement |
| 12 months, 24 hours | timekeeping |
| dozen, gross | trade quantities |
English eleven and twelve come from Old English forms meaning "one left over" and "two left over" — left over after ten. Twelve is convenient because it divides by 2, 3, 4 and 6, which matters when you are splitting goods without fractions.
Counting the finger joints with the thumb gives twelve per hand, which is the usual explanation for duodecimal systems in the Middle East and South Asia.
Base sixty runs our clocks
Babylonian mathematics used base sixty, and it is still in daily use: 60 seconds, 60 minutes, 360 degrees. Sixty divides evenly by 2, 3, 4, 5, 6, 10, 12, 15, 20 and 30 — an unusually convenient property before decimal fractions existed.
It has survived four thousand years and multiple attempts to decimalise it, including a French Revolutionary decimal clock that lasted barely a year.
Body-part counting
Several languages of New Guinea use extended body-part tallies rather than abstract numerals, counting up one arm, across the head and down the other side. Each number is the name of a body part, and the sequence must be memorised in order. Systems of this kind typically top out somewhere between twenty and forty.
These are not deficient systems — they are adapted to contexts where large exact quantities rarely need to be expressed, and they become limiting only when a society's needs change.
Languages that regularised
| Number | English | Mandarin | Japanese |
|---|---|---|---|
| 11 | eleven | shí yī — ten one | jū ichi — ten one |
| 12 | twelve | shí èr — ten two | jū ni — ten two |
| 20 | twenty | èr shí — two ten | ni jū — two ten |
| 35 | thirty-five | sān shí wǔ | san jū go |
East Asian number words are fully transparent — every number above ten is built by a visible rule with no irregular forms. Studies of early arithmetic learning have repeatedly noted that children learning these systems grasp place value earlier, which is a plausible small advantage attributable directly to the language.
What it means for learners
Numbers are among the first things you need and among the last to become automatic, because they must be processed fast under pressure — prices, times, platform numbers. Irregular systems like French and Danish need deliberate drilling well beyond the point where the rest of your vocabulary feels comfortable.
Practise with real quantities rather than lists: read prices, say years aloud, tell the time in the target language. That is what converts a memorised sequence into something you can use at the speed a cashier speaks.
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Open the dictionary appFrequently asked questions
Why do most languages count in tens?
Almost certainly because humans have ten fingers. Base twenty systems generally reflect counting fingers and toes, and several languages have explicit words meaning whole person for twenty — the connection to body-based counting is direct.
Why are there 60 minutes in an hour?
The system is inherited from Babylonian mathematics, which used base sixty. Sixty divides evenly by 2, 3, 4, 5, 6, 10, 12, 15, 20 and 30, which made fractions convenient in an era before decimal notation. Degrees in a circle come from the same source.
Do any languages have very few number words?
Some have been reported with limited numeral inventories, most famously Pirahã in the Amazon, described as having only approximate quantity terms rather than exact numerals. Such reports are debated, but restricted numeral systems are well attested in several small languages.