# Quinary

Numeral systems |
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Hindu–Arabic numeral system |

East Asian |

Alphabetic |

Former |

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Non-standard positional numeral systems |

List of numeral systems |

**Quinary** (**base-5**) is a numeral system with five as the base. A possible origination of a quinary system is that there are five fingers on either hand. The base five is stated from 0–4.

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.

As five is a prime number, only the reciprocals of the powers of five terminate, although its location between two highly composite numbers (4 and 6) guarantees that many recurring fractions have relatively short periods.

Today, the main usage of base 5 is as a biquinary system, which is decimal using five as a sub-base. Another example of a sub-base system, is sexagesimal, base 60, which used 10 as a sub-base.

Each quinary digit has log_{2}5 (approx. 2.32) bits of information.^{[1]}

## Comparison to other radices

× | 1 | 2 | 3 | 4 | 10 | 11 | 12 | 13 | 14 | 20 |

1 | 1 | 2 | 3 | 4 | 10 | 11 | 12 | 13 | 14 | 20 |

2 | 2 | 4 | 11 | 13 | 20 | 22 | 24 | 31 | 33 | 40 |

3 | 3 | 11 | 14 | 22 | 30 | 33 | 41 | 44 | 102 | 110 |

4 | 4 | 13 | 22 | 31 | 40 | 44 | 103 | 112 | 121 | 130 |

10 | 10 | 20 | 30 | 40 | 100 | 110 | 120 | 130 | 140 | 200 |

11 | 11 | 22 | 33 | 44 | 110 | 121 | 132 | 143 | 204 | 220 |

12 | 12 | 24 | 41 | 103 | 120 | 132 | 144 | 211 | 223 | 240 |

13 | 13 | 31 | 44 | 112 | 130 | 143 | 211 | 224 | 242 | 310 |

14 | 14 | 33 | 102 | 121 | 140 | 204 | 223 | 242 | 311 | 330 |

20 | 20 | 40 | 110 | 130 | 200 | 220 | 240 | 310 | 330 | 400 |

Quinary | 0 | 1 | 2 | 3 | 4 | 10 | 11 | 12 | 13 | 14 | 20 | 21 | 22 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|

Binary | 0 | 1 | 10 | 11 | 100 | 101 | 110 | 111 | 1000 | 1001 | 1010 | 1011 | 1100 |

Decimal | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |

Quinary | 23 | 24 | 30 | 31 | 32 | 33 | 34 | 40 | 41 | 42 | 43 | 44 | 100 |

Binary | 1101 | 1110 | 1111 | 10000 | 10001 | 10010 | 10011 | 10100 | 10101 | 10110 | 10111 | 11000 | 11001 |

Decimal | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 |

Decimal (periodic part) | Quinary (periodic part) |
Binary (periodic part) |

1/2 = 0.5 | 1/2 = 0.2 |
1/10 = 0.1 |

1/3 = 0.3 |
1/3 = 0.13 |
1/11 = 0.01 |

1/4 = 0.25 | 1/4 = 0.1 |
1/100 = 0.01 |

1/5 = 0.2 | 1/10 = 0.1 |
1/101 = 0.0011 |

1/6 = 0.16 |
1/11 = 0.04 |
1/110 = 0.010 |

1/7 = 0.142857 |
1/12 = 0.032412 |
1/111 = 0.001 |

1/8 = 0.125 | 1/13 = 0.03 |
1/1000 = 0.001 |

1/9 = 0.1 |
1/14 = 0.023421 |
1/1001 = 0.000111 |

1/10 = 0.1 | 1/20 = 0.02 |
1/1010 = 0.00011 |

1/11 = 0.09 |
1/21 = 0.02114 |
1/1011 = 0.0001011101 |

1/12 = 0.083 |
1/22 = 0.02 |
1/1100 = 0.0001 |

1/13 = 0.076923 |
1/23 = 0.0143 |
1/1101 = 0.000100111011 |

1/14 = 0.0714285 |
1/24 = 0.013431 |
1/1110 = 0.0001 |

1/15 = 0.06 |
1/30 = 0.013 |
1/1111 = 0.0001 |

1/16 = 0.0625 | 1/31 = 0.0124 |
1/10000 = 0.0001 |

1/17 = 0.0588235294117647 |
1/32 = 0.0121340243231042 |
1/10001 = 0.00001111 |

1/18 = 0.05 |
1/33 = 0.011433 |
1/10010 = 0.0000111 |

1/19 = 0.052631578947368421 |
1/34 = 0.011242141 |
1/10011 = 0.000011010111100101 |

1/20 = 0.05 | 1/40 = 0.01 |
1/10100 = 0.000011 |

1/21 = 0.047619 |
1/41 = 0.010434 |
1/10101 = 0.000011 |

1/22 = 0.045 |
1/42 = 0.01032 |
1/10110 = 0.00001011101 |

1/23 = 0.0434782608695652173913 |
1/43 = 0.0102041332143424031123 |
1/10111 = 0.00001011001 |

1/24 = 0.0416 |
1/44 = 0.01 |
1/11000 = 0.00001 |

1/25 = 0.04 | 1/100 = 0.01 |
1/11001 = 0.00001010001111010111 |

## Usage

Many languages^{[2]} use quinary number systems, including Gumatj, Nunggubuyu,^{[3]} Kuurn Kopan Noot,^{[4]} Luiseño^{[5]} and Saraveca. Gumatj is a true "5–25" language, in which 25 is the higher group of 5. The Gumatj numerals are shown below:^{[3]}

Number | Base 5 | Numeral |
---|---|---|

1 | 1 | wanggany |

2 | 2 | marrma |

3 | 3 | lurrkun |

4 | 4 | dambumiriw |

5 | 10 | wanggany rulu |

10 | 20 | marrma rulu |

15 | 30 | lurrkun rulu |

20 | 40 | dambumiriw rulu |

25 | 100 | dambumirri rulu |

50 | 200 | marrma dambumirri rulu |

75 | 300 | lurrkun dambumirri rulu |

100 | 400 | dambumiriw dambumirri rulu |

125 | 1000 | dambumirri dambumirri rulu |

625 | 10000 | dambumirri dambumirri dambumirri rulu |

In the video game Riven and subsequent games of the Myst franchise, the D'ni language uses a quinary numeral system.

## Biquinary

A decimal system with 2 and 5 as a sub-bases is called biquinary, and is found in Wolof and Khmer. 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**.

Most 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. Units of currencies are commonly partially or wholly biquinary.

## Quadquinary

A vigesimal system with 4 and 5 as a sub-bases is found in Nahuatl and the Maya numerals.

## See also

## References

References:

- ↑ http://logbase2.blogspot.ca/2007/12/log-base-2.html
- ↑ Harald Hammarström, Rarities in Numeral Systems: "Bases 5, 10, and 20 are omnipresent." doi:10.1515/9783110220933.11
- 1 2 Harris, John (1982), Hargrave, Susanne, ed., "Facts and fallacies of aboriginal number systems" (PDF),
*Work Papers of SIL-AAB Series B*,**8**: 153–181 - ↑ Dawson, J. "Australian Aborigines: The Languages and Customs of Several Tribes of Aborigines in the Western District of Victoria (1881), p. xcviii.
- ↑ Closs, Michael P.
*Native American Mathematics*. ISBN 0-292-75531-7.

## External links

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