Nonary

Nonary is a base-9 numeral system, typically using the digits 0-8, but not the digit 9.

The first few numbers in decimal and nonary are:

Decimal	1	2	3	4	5	6	7	8	9	10	11	12	13
Nonary	1	2	3	4	5	6	7	8	10	11	12	13	14

The multiplication table in nonary is:

*	1	2	3	4	5	6	7	8
1	1	2	3	4	5	6	7	8
2	2	4	6	8	11	13	15	17
3	3	6	10	13	16	20	23	26
4	4	8	13	17	22	26	31	35
5	5	11	16	22	27	33	38	44
6	6	13	20	26	33	40	46	53
7	7	15	23	31	38	46	54	62
8	8	17	26	35	44	53	62	71

Nonary notation can be used as a concise representation of ternary data. This is similar to using quaternary notation for binary data, though the digit set is closer in size to octal.

Except for three, no primes in nonary end in 0, 3 or 6, since any nonary number ending in 0, 3 or 6 is divisible by three.

A nonary number is divisible by two, four or eight, if the sum of its digits is also divisible by two, four or eight respectively.

If x is a triangular number, so is 9x+1. This means that one finds 3, 31, 311, 3111, 31111... in the triangular numbers. Likewise, 6, 61, 611, 6111, ....

In popular culture

Although the term "Nonary" is used in describing the written form of the language used by the fictional civilization, The Culture, found in Iain M. Banks' books, the description on page 119 of Excession reads more like it's based on a binary system with a 9-bit 'byte'.

The "Nonary Game" is the game played by the characters in the 2009 Nintendo DS video game, 999: Nine Hours, Nine Persons, Nine Doors. Much of the game revolves around the number nine, hence the name.

See also

• Numeral system

External links

• The first 1000 counting numbers in base 9-scientific-library.com