Quinary (base-5 or pental) is a

numeral system A numeral system (or system of numeration) is a writing system for expressing numbers; that is, a mathematical notation for representing numbers of a given set, using digits or other symbols in a consistent manner. The same sequence of symbo ...

with

five 5 is a number, numeral, and glyph. 5, five or number 5 may also refer to: * AD 5, the fifth year of the AD era * 5 BC, the fifth year before the AD era Literature * ''5'' (visual novel), a 2008 visual novel by Ram * ''5'' (comics), an awa ...

as the base. A possible origination of a quinary system is that there are five digits on either

hand A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each "h ...

. In the quinary place system, five numerals, from 0 to 4, are used to represent any

real number In mathematics, a real number is a number that can be used to measure a ''continuous'' one-dimensional quantity such as a distance, duration or temperature. Here, ''continuous'' means that values can have arbitrarily small variations. Every ...

. According to this method,

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 The decimal numeral system (also called the base-ten positional numeral system and denary or decanary) is the standard system for denoting integer and non-integer numbers. It is the extension to non-integer numbers of the Hindu–Arabic numeral ...

using five as a

sub-base In highway engineering, subbase is the layer of aggregate material laid on the subgrade, on which the base course layer is located. It may be omitted when there will be only foot traffic on the pavement, but it is necessary for surfaces used by ...

. Another example of a sub-base system, is

sexagesimal Sexagesimal, also known as base 60 or sexagenary, is a numeral system with sixty as its base. It originated with the ancient Sumerians in the 3rd millennium BC, was passed down to the ancient Babylonians, and is still used—in a modified form ...

, base 60, which used 10 as a sub-base. Each quinary digit can hold log₂5 (approx. 2.32) bits of information.

Comparison to other radices

Usage

Many languagesHarald Hammarström, Rarities in Numeral Systems: "Bases 5, 10, and 20 are omnipresent." use quinary number systems, including Gumatj, Nunggubuyu, Kuurn Kopan Noot, Luiseño and Saraveca. Gumatj has been reported to be a true "5–25" language, in which 25 is the higher group of 5. The Gumatj numerals are shown below: However, Harald Hammarström reports "one would not usually use exact numbers for counting this high in this language and there is a certain likelihood that the system was extended this high only at the time of elicitation with one single speaker", pointing to the Biwat language as a similar case (previously attested as 5-20, but with one speaker recorded as making an innovation to turn it 5-25).

Biquinary

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

Roman numeral Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers are written with combinations of letters from the Latin alphabet, ea ...

s are an early biquinary system. The numbers 1, 5, 10, and 50 are written as I, V, X, and L respectively. Seven is VII and seventy is LXX. The full list is: Note that these are not positional number systems. In theory a number such as 73 could be written as IIIXXL without ambiguity as well as LXXIII and it is still not possible to extend it beyond thousands. There is also no sign for zero. But with the introduction of inversions such as IV and IX, it was necessary to keep the order from most to least significant. Many versions of the

abacus The abacus (''plural'' abaci or abacuses), also called a counting frame, is a calculating tool which has been used since ancient times. It was used in the ancient Near East, Europe, China, and Russia, centuries before the adoption of the Hi ...

, such as the suanpan and soroban, use a biquinary system to simulate a decimal system for ease of calculation.

Urnfield culture numerals Proto-writing consists of visible marks communicating limited information. Such systems emerged from earlier traditions of symbol systems in the early Neolithic, as early as the 7th millennium BC in Eastern Europe and China. They used ideog ...

and some tally mark systems are also biquinary. Units of currencies are commonly partially or wholly biquinary.

Bi-quinary coded decimal Bi-quinary coded decimal is a numeral encoding scheme used in many abacuses and in some early computers, including the Colossus. The term ''bi-quinary'' indicates that the code comprises both a two-state (''bi'') and a five-state (''quin''ary) ...

is a variant of biquinary that was used on a number of early computers including

Colossus Colossus, Colossos, or the plural Colossi or Colossuses, may refer to: Statues * Any exceptionally large statue ** List of tallest statues ** :Colossal statues * ''Colossus of Barletta'', a bronze statue of an unidentified Roman emperor * ''Col ...

and the

IBM 650 The IBM 650 Magnetic Drum Data-Processing Machine is an early digital computer produced by IBM in the mid-1950s. It was the first mass produced computer in the world. Almost 2,000 systems were produced, the last in 1962, and it was the fir ...

to represent decimal numbers.

Quadquinary

vigesimal vigesimal () or base-20 (base-score) numeral system is based on twenty (in the same way in which the decimal numeral system is based on ten). '' Vigesimal'' is derived from the Latin adjective '' vicesimus'', meaning 'twentieth'. Places In a ...

system with 4 and 5 as a sub-bases is found in

Nahuatl Nahuatl (; ), Aztec, or Mexicano is a language or, by some definitions, a group of languages of the Uto-Aztecan language family. Varieties of Nahuatl are spoken by about Nahua peoples, most of whom live mainly in Central Mexico and have small ...

Calculators and programming languages

Few

calculator An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics. The first solid-state electronic calculator was created in the early 1960s. Pocket-sized ...

s support calculations in the quinary system, except for some

Sharp Sharp or SHARP may refer to: Acronyms * SHARP (helmet ratings) (Safety Helmet Assessment and Rating Programme), a British motorcycle helmet safety rating scheme * Self Help Addiction Recovery Program, a charitable organisation founded in 199 ...

models (including some of the EL-500W and EL-500X series, where it is named the ''pental system'') since about 2005, as well as the open-source scientific calculator WP 34S. Python's int() function supports conversion of numeral systems from any base to base 10. Thus, the quinary number 101 is evaluated using int('101',5) as 26.

References

External links

Quinary Base Conversion
includes fractional part, from Math Is Fun * {{commons category inline, Quinary numeral system

uses

D'ni ''Myst'' is a franchise centered on a series of adventure video games. The first game in the series, ''Myst'', was released in 1993 by brothers Rand and Robyn Miller and their video game company Cyan, Inc. The first sequel to ''Myst'', ''Riven' ...

numerals from the

Myst ''Myst'' is a graphic adventure/puzzle video game designed by the Miller brothers, Robyn and Rand. It was developed by Cyan, Inc., published by Broderbund, and initially released for the Macintosh in 1993. In the game, the player's charact ...

franchise, integers only, fan-made. Positional numeral systems 5 (number)