Dzongkha numerals

Dzongkha, the national language of Bhutan, has two numeral systems, one vigesimal (base 20), and a modern decimal system. The vigesimal system remains in robust use. Ten is an auxiliary base: the -teens are formed with ten and the numerals 1–9. Ex. cu_ci

Vigesimal
* When it appears on its own, 'ten' is usually said  'a full ten'. In combinations it is simply .

Multiples of 20 are formed from . Intermediate multiples of ten are formed with  'half to':

400 (20²) ' is the next unit: ' 400, ' 800, etc. Higher powers are 8000 (20³) ' ('a ɡreat score') and  160,000 (20⁴).

Decimal
The decimal system is the same up to 19. Then decades, however, are formed as unit–ten, as in Chinese, and the hundreds similarly. 20 is reported to be , the same as vigesimal numeral 400; this may be lexical interference for the expected. (In any case, there is no ambiguity, because as 400 it is obligatorily ' 'one 400'.) Several of the decades have an epenthetic ', perhaps by analogy with 18 and 19, where the  presumably reflects a historical 'ten':


 * ' 30, ' 40, ' 50, ' or ' 100 (a 'full hundred' or 'one hundred'), ' 200, ' 300, ' 400, etc.