Na'vi/Numbers

As the Naʼvi have four digits per hand, they have a ("octal") number system. Until recently, they only counted up to sixteen, their number of fingers and toes, any number greater than that being simply pxay "many".

There are s for the numbers one through eight. Above that, one counts eight-one for nine, eight-two for ten, etc., until sixteen, which is two eights. At sixty-four (eight eights), a new numeral comes in, zam, which is the octal equivalent of decimal 'hundred'.

Cardinal numbers
The second series above continues with mevoláw 'two-eights-one', mevomún 'two-eights-two', etc.; the units are similarly suffixed to the other multiples of eight. Thus all numbers up to at least kivohín "sixty-three" (octal 77) are single words. Numbers between zam and mezam (one-hundred twenty-eight, octal 200) are not attested. The 'hundreds' continue with pxezam etc. Higher orders are vozam 512 (octal 1000: thus mevozam for octal 2000 etc.) and zazam 4096 (octal 10,000: thus mezazam for octal 20,000 etc.).

When a number modifies a noun, the singular form is used for the noun. In addition, as an attributive, the number itself requires the attributive affix a:
 * zìsìt amrr "five years",
 * ʼawa tìpawmìri "regarding one (particular) question",
 * munea ʼeveng "two children"

(compare meveng "children" when there are two of them).

Ordinal numbers
Ordinal numbers take the (unstressed) suffix -ve. However, the forms are somewhat irregular; they are generally based on the short/combining forms of the numerals, but "third" and "eighth" are based on the long/final forms. The series continues with mevoláwve "seventeenth (21st)", etc. *Zamve (*zave ?) is not attested. As these are adjectives, they take a when modifying nouns directly: aʼáwve / ʼáwvea, etc.

Converting between octal and decimal
Conversion from English decimal to Naʼvi octal numbers can be tedious. It may be easier to count on your fingers by tucking in your pinkies so that you have the same eight fingers as a Naʼvi has: English "ten" is therefore 1 set of hands plus 2 extra fingers, or Naʼvi 12 vomun. Converting from Naʼvi back to English is more straightforward, if you think of the Naʼvi number as so-many eights plus so-many: Naʼvi "72", for example, would be "seven eights (7×8=56) and two", or English 58. Because eight is a power in binary arithmetic, many of the Naʼvi numbers are also binary units which may be familiar from computing; vozam (octal 1000), for example, is decimal 512.

Derivations of numbers
Numerals form various derivatives, such as ʼawpo "an individual", nìʼawve "first(ly)" (as in, "I was here first"), ʼawsiténg "together" (one-make-same), kawtu "no-one" (not-one-person), kawkrr "never" (not-one-time), nìʼaw "only" (one-ly), and nìʼawtu "alone" (one-person-ly), all from ʼaw "one"; also nìmun "again" (second-ly) and perhaps muntxa "mated" from mune "two".

There are two words for "once", ʼawlie and ʼawlo, the difference of which is not clear. "Twice" is melo.