Quinary (base-5) is a numeral system with five as the base. This originates from the five fingers on either hand.

In the quinary place system, five numerals from 0 to 4, are used to represent any real number. According to this method, five is written as 10, twenty-five is written as 100 and sixty is written as 220.

Usage

Many languages use quinary number systems, including Gumatj, Nunggubuyu,, Kuurn Kopan Noot and Saraveca. Of these, Gumatj is the only true "5-25" language known, in which 25 is the higher group of 5. The Gumatj numerals are shown below:

Number	Numeral
1	wanggany
2	marrma
3	lurrkun
4	dambumiriw
5	wanggany rulu
10	marrma rulu
15	lurrkun rulu
20	dambumiriw rulu
25	dambumirri rulu
50	marrma dambumirri rulu
75	lurrkun dambumirri rulu
100	dambumiriw dambumirri rulu
125	dambumirri dambumirri rulu
625	dambumirri dambumirri dambumirri rulu

A decimal system with 5 as a sub-base is called biquinary, and is found in Wolof and Khmer. A vigesimal system with 5 as a sub-base is found in Nahuatl and the Maya numerals.

Roman numerals are a biquinary system. The numbers 1, 5, 10, and 50 are written as I, V, X, and L respectively. Eight is VIII and seventy is LXX.

The Chinese and Japanese versions of the abacus use a biquinary system to simulate a decimal system for ease of calculation.

Urnfield culture numerals and some tally mark systems are also biquinary.

References

See also

• Pentimal system

External links

• Quinary Base Conversion, includes fractional part, from Math Is Fun