List of numeral system topics
Encyclopedia
This is a list of numeral system
topics and "numeric representations". It does not systematically list computer formats for storing numbers, see also: computer numbering formats
and number names
.
Numeral system
A numeral system is a writing system for expressing numbers, that is a mathematical notation for representing numbers of a given set, using graphemes or symbols in a consistent manner....
topics and "numeric representations". It does not systematically list computer formats for storing numbers, see also: computer numbering formats
Computer numbering formats
A computer number format is the internal representation of numeric values in digital computer and calculator hardware and software.-Bits:The concept of a bit can be understood as a value of either 1 or 0, on or off, yes or no, true or false, or encoded by a switch or toggle of some kind...
and number names
Number names
In linguistics, number names are specific words in a natural language that represent numbers.In writing, numerals are symbols also representing numbers...
.
Arranged by base
- RadixRadixIn mathematical numeral systems, the base or radix for the simplest case is the number of unique digits, including zero, that a positional numeral system uses to represent numbers. For example, for the decimal system the radix is ten, because it uses the ten digits from 0 through 9.In any numeral...
, radix pointRadix pointIn mathematics and computing, a radix point is the symbol used in numerical representations to separate the integer part of a number from its fractional part . "Radix point" is a general term that applies to all number bases...
, mixed radixMixed radixMixed radix numeral systems are non-standard positional numeral systems in which the numerical base varies from position to position. Such numerical representation applies when a quantity is expressed using a sequence of units that are each a multiple of the next smaller one, but not by the same...
, base (mathematics) - Unary numeral systemUnary numeral systemThe unary numeral system is the bijective base-1 numeral system. It is the simplest numeral system to represent natural numbers: in order to represent a number N, an arbitrarily chosen symbol representing 1 is repeated N times. For example, using the symbol | , the number 6 is represented as ||||||...
(base 1)- Tally marksTally marksTally marks, or hash marks, are a unary numeral system. They are a form of numeral used for counting. They allow updating written intermediate results without erasing or discarding anything written down...
- Tally marks
- Binary numeral systemBinary numeral systemThe binary numeral system, or base-2 number system, represents numeric values using two symbols, 0 and 1. More specifically, the usual base-2 system is a positional notation with a radix of 2...
(base 2) - Negative baseNegative baseA negative base may be used to construct a non-standard positional numeral system. Like other place-value systems, each position holds multiples of the appropriate power of the system's base; but that base is negative—that is to say, the base \scriptstyle b is equal to \scriptstyle -r for some...
numeral system (base −2) - Ternary numeral systemTernary numeral systemTernary is the base- numeral system. Analogous to a bit, a ternary digit is a trit . One trit contains \log_2 3 bits of information...
numeral system (base 3) - Balanced ternaryBalanced ternaryBalanced ternary is a non-standard positional numeral system , useful for comparison logic. It is a ternary system, but unlike the standard ternary system, the digits have the values −1, 0, and 1...
numeral system (base 3) - Negative baseNegative baseA negative base may be used to construct a non-standard positional numeral system. Like other place-value systems, each position holds multiples of the appropriate power of the system's base; but that base is negative—that is to say, the base \scriptstyle b is equal to \scriptstyle -r for some...
numeral system (base −3) - Quaternary numeral systemQuaternary numeral systemQuaternary is the base- numeral system. It uses the digits 0, 1, 2 and 3 to represent any real number.It shares with all fixed-radix numeral systems many properties, such as the ability to represent any real number with a canonical representation and the characteristics of the representations of...
(base 4) - Quater-imaginary baseQuater-imaginary baseThe quater-imaginary numeral system was first proposed by Donald Knuth in 1955, in a submission to a high-school science talent search. It is a non-standard positional numeral system which uses the imaginary number 2i as its base. It is able to uniquely represent every complex number using only...
(base 2√−1) - QuinaryQuinaryQuinary 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...
numeral system (base 5)- Pentimal systemPentimal systemThe pentimal system is a notation for presenting numbers, usually by inscribing in wood or stone. The notation has been used in Scandinavia, usually in conjunction to runes....
- Pentimal system
- SenarySenaryIn mathematics, a senary numeral system is a base- numeral system.Senary may be considered useful in the study of prime numbers since all primes other than 2 and 3, when expressed in base-six, have 1 or 5 as the final digit...
numeral system (base 6) - SeptenarySeptenaryThe septenary numeral system is the base- number system, and uses the digits 0-6.-Multiplication table:-Fractions:Fractions expressed in septenary will repeat a sequence of digits unless the denominator is a power of seven...
numeral system (base 7) - OctalOctalThe octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Numerals can be made from binary numerals by grouping consecutive binary digits into groups of three...
numeral system (base 8) - NonaryNonaryNonary is a base- numeral system, typically using the digits 0-8, but not the digit 9.The first few numbers in nonary and decimal are:Nonary 1 2 3 4 5 6 7 81011121314Decimal 1 2 3 4 5 6 7 8 910111213The...
(novenary) numeral system (base 9) - DecimalDecimalThe decimal numeral system has ten as its base. It is the numerical base most widely used by modern civilizations....
(denary) numeral system (base 10)- Bi-quinary coded decimalBi-quinary coded decimalBi-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 and a five-state component...
- Bi-quinary coded decimal
- Negative baseNegative baseA negative base may be used to construct a non-standard positional numeral system. Like other place-value systems, each position holds multiples of the appropriate power of the system's base; but that base is negative—that is to say, the base \scriptstyle b is equal to \scriptstyle -r for some...
numeral system (base −10) - DuodecimalDuodecimalThe duodecimal system is a positional notation numeral system using twelve as its base. In this system, the number ten may be written as 'A', 'T' or 'X', and the number eleven as 'B' or 'E'...
(dozenal) numeral system (base 12) - HexadecimalHexadecimalIn mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
numeral system (base 16) - VigesimalVigesimalThe vigesimal or base 20 numeral system is based on twenty .- Places :...
numeral system (base 20) - Sexagesimal numeral system (base 60)
Arranged by culture
- Australian Aboriginal enumerationAustralian Aboriginal enumerationA common misconception among non-Aboriginals is that Aboriginals did not have a way to count beyond two or three. However, Alfred Howitt, who studied the peoples of southeastern Australia, disproved this in the late nineteenth century, although the myth continues in circulation today.The...
- Armenian numeralsArmenian numeralsThe system of Armenian numerals is a historic numeral system created using the majuscules of the Armenian alphabet.There was no notation for zero in the old system, and the numeric values for individual letters were added together. The principles behind this system are the same as for the Ancient...
- Babylonian numeralsBabylonian numeralsBabylonian numerals were written in cuneiform, using a wedge-tipped reed stylus to make a mark on a soft clay tablet which would be exposed in the sun to harden to create a permanent record....
- Chinese numeralsChinese numeralsChinese numerals are characters for writing numbers in Chinese. Today speakers of Chinese use three numeral systems:the ubiquitous Arabic numerals and two indigenous systems....
- Counting rodsCounting rodsCounting rods are small bars, typically 3–14 cm long, used by mathematicians for calculation in China, Japan, Korea, and Vietnam. They are placed either horizontally or vertically to represent any number and any fraction....
- Counting rods
- Aegean numbers
- Greek numeralsGreek numeralsGreek numerals are a system of representing numbers using letters of the Greek alphabet. They are also known by the names Ionian numerals, Milesian numerals , Alexandrian numerals, or alphabetic numerals...
- Hebrew numeralsHebrew numeralsThe system of Hebrew numerals is a quasi-decimal alphabetic numeral system using the letters of the Hebrew alphabet.In this system, there is no notation for zero, and the numeric values for individual letters are added together...
- Hindu–Arabic numeral system
- Arabic numeralsArabic numeralsArabic numerals or Hindu numerals or Hindu-Arabic numerals or Indo-Arabic numerals are the ten digits . They are descended from the Hindu-Arabic numeral system developed by Indian mathematicians, in which a sequence of digits such as "975" is read as a numeral...
- Indian numeralsIndian numeralsMost of the positional base 10 numeral systems in the world have originated from India, where the concept of positional numeration was first developed...
- Thai numeralsThai numeralsThai numerals constitute a numeral system of Thai number names for the Khmer numerals traditionally used in Thailand, also used for the more common Arabic numerals, and which follow the Hindu-Arabic numeral system.-Usage:...
- Arabic numerals
- Japanese numeralsJapanese numeralsThe system of Japanese numerals is the system of number names used in the Japanese language. The Japanese numerals in writing are entirely based on the Chinese numerals and the grouping of large numbers follow the Chinese tradition of grouping by 10,000...
- Korean numeralsKorean numeralsThe Korean language has two regularly used sets of numerals, a native Korean system and Sino-Korean system.-Construction:For both native and Sino- Korean numerals, the teens are represented by a combination of tens and the ones places...
- Maya numeralsMaya numeralsMaya Numerals were a vigesimal numeral system used by the Pre-Columbian Maya civilization.The numerals are made up of three symbols; zero , one and five...
- Moksha numerals
- Prehistoric numerals
- Roman numeralsRoman numeralsThe numeral system of ancient Rome, or Roman numerals, uses combinations of letters from the Latin alphabet to signify values. The numbers 1 to 10 can be expressed in Roman numerals as:...
- Welsh numeralsWelsh numeralsThe traditional counting system used in the Welsh language is vigesimal, i.e. based on twenties, as in the French numerals for 60-99, where numbers from 11–14 are "x on ten", 16–19 are "x on fifteen" ; numbers from 21–39 are "1–19 on twenty", 40 is "two twenty", 60 is "three twenty", etc.There is...
Other
- AlgorismAlgorismAlgorism is the technique of performing basic arithmetic by writing numbers in place value form and applying a set of memorized rules and facts to the digits. One who practices algorism is known as an algorist...
- Goodstein's theoremGoodstein's theoremIn mathematical logic, Goodstein's theorem is a statement about the natural numbers, made by Reuben Goodstein, which states that every Goodstein sequence eventually terminates at 0. showed that it is unprovable in Peano arithmetic...
- MyriadMyriadMyriad , "numberlesscountless, infinite", is a classical Greek word for the number 10,000. In modern English, the word refers to an unspecified large quantity.-History and usage:...
- Non-standard positional numeral systemsNon-standard positional numeral systemsNon-standard positional numeral systems here designates numeral systems that may be denoted positional systems, but that deviate in one way or another from the following description of standard positional systems:...
- QuipuQuipuQuipus or khipus were recording devices used in the Inca Empire and its predecessor societies in the Andean region. A quipu usually consisted of colored, spun, and plied thread or strings from llama or alpaca hair. It could also be made of cotton cords...
- Long and short scalesLong and short scalesThe long and short scales are two of several different large-number naming systems used throughout the world for integer powers of ten. Many countries, including most in continental Europe, use the long scale whereas most English-speaking countries use the short scale...
- Tally stickTally stickA tally was an ancient memory aid device to record and document numbers, quantities, or even messages. Tally sticks first appear as notches carved on animal bones, in the Upper Paleolithic. A notable example is the Ishango Bone...
- Tally mark
- -yllion-yllion-yllion is a proposal from Donald Knuth for the terminology and symbols of an alternate decimal superbase system. In it, he adapts the familiar English terms for large numbers to provide a systematic set of names for much larger numbers...