From HandWiki - Reading time: 16 min
| Numeral systems |
|---|
| Hindu–Arabic numeral system |
| East Asian |
| Alphabetic |
| Former |
| Positional systems by base |
| Non-standard positional numeral systems |
| List of numeral systems |
There are many different numeral systems, that is, writing systems for expressing numbers.
"A base is a natural number B whose powers (B multiplied by itself some number of times) are specially designated within a numerical system."[1]: 38 The term is not equivalent to radix, as it applies to all numerical notation systems (not just positional ones with a radix) and most systems of spoken numbers.[1] Some systems have two bases, a smaller (subbase) and a larger (base); an example is Roman numerals, which are organized by fives (V=5, L=50, D=500, the subbase) and tens (X=10, C=100, M=1,000, the base).
[3]| Name | Base | Sample | Approx. First Appearance |
|---|---|---|---|
| Proto-cuneiform numerals | 10&60 | -3500 c. 3500–2000 BCE
| |
| Indus numerals | unknown[2] | -3501 c. 3500–1900 BCE | |
| Proto-Elamite numerals | 10&60 | -3101 3100 BCE
| |
| Sumerian numerals | 10&60 | -3100 3100 BCE
| |
| Egyptian numerals | 10 | <hiero size=8>Z1 V20 V1 M12 D50 I8 I7 C11</hiero> | -3000 3000 BCE
|
| Babylonian numerals | 10&60 | 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px | -2000 2000 BCE
|
| Aegean numerals | 10 | 𐄇 𐄈 𐄉 𐄊 𐄋 𐄌 𐄍 𐄎 𐄏 ( 𐄐 𐄑 𐄒 𐄓 𐄔 𐄕 𐄖 𐄗 𐄘 ( 𐄙 𐄚 𐄛 𐄜 𐄝 𐄞 𐄟 𐄠 𐄡 ( 𐄢 𐄣 𐄤 𐄥 𐄦 𐄧 𐄨 𐄩 𐄪 ( 𐄫 𐄬 𐄭 𐄮 𐄯 𐄰 𐄱 𐄲 𐄳 ( |
-1500 1500 BCE
|
| Chinese numerals Japanese numerals Korean numerals (Sino-Korean) Vietnamese numerals (Sino-Vietnamese) |
10 |
零一二三四五六七八九十百千萬億 (Default, Traditional Chinese) |
-1300 1300 BCE
|
| Roman numerals | 5&10 | I V X L C D M | -1000 1000 BCE |
| Hebrew numerals | 10 | א ב ג ד ה ו ז ח ט י כ ל מ נ ס ע פ צ ק ר ש ת ך ם ן ף ץ |
-800 800 BCE
|
| Indian numerals | 10 |
Bengali ০ ১ ২ ৩ ৪ ৫ ৬ ৭ ৮ ৯ Devanagari ० १ २ ३ ४ ५ ६ ७ ८ ९ Gujarati ૦ ૧ ૨ ૩ ૪ ૫ ૬ ૭ ૮ ૯ Kannada ೦ ೧ ೨ ೩ ೪ ೫ ೬ ೭ ೮ ೯ Malayalam ൦ ൧ ൨ ൩ ൪ ൫ ൬ ൭ ൮ ൯ Odia ୦ ୧ ୨ ୩ ୪ ୫ ୬ ୭ ୮ ୯ Punjabi ੦ ੧ ੨ ੩ ੪ ੫ ੬ ੭ ੮ ੯ Tamil ௦ ௧ ௨ ௩ ௪ ௫ ௬ ௭ ௮ ௯ Telugu ౦ ౧ ౨ ౩ ౪ ౫ ౬ ౭ ౮ ౯ Tibetan ༠ ༡ ༢ ༣ ༤ ༥ ༦ ༧ ༨ ༩ Urdu ۰ ۱ ۲ ۳ ۴ ۵ ۶ ۷ ۸ ۹ |
-750 750–500 BCE
|
| Greek numerals | 10 | ō α β γ δ ε ϝ ζ η θ ι ο Αʹ Βʹ Γʹ Δʹ Εʹ Ϛʹ Ζʹ Ηʹ Θʹ |
-400 <400 BCE
|
| Kharosthi numerals | 4&10 | 𐩇 𐩆 𐩅 𐩄 𐩃 𐩂 𐩁 𐩀 | |
| Chinese rod numerals | 10 | 𝍠 𝍡 𝍢 𝍣 𝍤 𝍥 𝍦 𝍧 𝍨 𝍩 | 1 1st century
|
| Coptic numerals | 10 | Ⲁ Ⲃ Ⲅ Ⲇ Ⲉ Ⲋ Ⲍ Ⲏ Ⲑ | 100 2nd century
|
| Ge'ez numerals | 10 | ፩ ፪ ፫ ፬ ፭ ፮ ፯ ፰ ፱ ፲ ፳ ፴ ፵ ፶ ፷ ፸ ፹ ፺ ፻ ፼ [4] |
200 3rd–4th century
|
| Armenian numerals | 10 | Ա Բ Գ Դ Ե Զ Է Ը Թ Ժ | 400 Early 5th century
|
| Khmer numerals | 10 | ០ ១ ២ ៣ ៤ ៥ ៦ ៧ ៨ ៩ | 600 Early 7th century
|
| Thai numerals | 10 | ๐ ๑ ๒ ๓ ๔ ๕ ๖ ๗ ๘ ๙ | 601 7th century |
| Abjad numerals | 10 | غ ظ ض ذ خ ث ت ش ر ق ص ف ع س ن م ل ك ي ط ح ز و هـ د ج ب ا | 680 <8th century
|
| Chinese numerals (financial) | 10 | 零壹貳參肆伍陸柒捌玖拾佰仟萬億 (T. Chinese) 零壹贰叁肆伍陆柒捌玖拾佰仟萬億 (S. Chinese) |
690 late 7th/early 8th century |
| Eastern Arabic numerals | 10 | ٩ ٨ ٧ ٦ ٥ ٤ ٣ ٢ ١ ٠ | 701 8th century
|
| Vietnamese numerals (Chữ Nôm) | 10 | 𠬠 𠄩 𠀧 𦊚 𠄼 𦒹 𦉱 𠔭 𠃩 | 799 <9th century
|
| Western Arabic numerals | 10 | 0 1 2 3 4 5 6 7 8 9 | 801 9th century
|
| Glagolitic numerals | 10 | Ⰰ Ⰱ Ⰲ Ⰳ Ⰴ Ⰵ Ⰶ Ⰷ Ⰸ ... | 800 9th century
|
| Cyrillic numerals | 10 | а в г д е ѕ з и ѳ і ... | 900 10th century
|
| Rumi numerals | 10 | 900 10th century
| |
| Burmese numerals | 10 | ၀ ၁ ၂ ၃ ၄ ၅ ၆ ၇ ၈ ၉ | 1000 11th century |
| Tangut numerals | 10 | Template:Tangut | 1036 11th century (1036)
|
| Cistercian numerals | 10 | 1200 13th century
| |
| Maya numerals | 5&20 | 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px 15px 𝋠 𝋡 𝋢 𝋣 𝋤 𝋥 𝋦 𝋧 𝋨 𝋩 𝋪 𝋫 𝋬 𝋭 𝋮 𝋯 𝋰 𝋱 𝋲 𝋳 |
1400 15th century
|
| Muisca numerals | 20 | 1399 15th century
| |
| Korean numerals (Hangul) | 10 | 영 일 이 삼 사 오 육 칠 팔 구 | 1443 15th century (1443)
|
| Aztec numerals | 20 | x25px x25px x25px x25px x25px x25px x30px (1, 5, 20, 100, 400, 800, 8000) |
1500 16th century
|
| Sinhala numerals | 10 | ෦ ෧ ෨ ෩ ෪ ෫ ෬ ෭ ෮ ෯ 𑇡 𑇢 𑇣 𑇤 𑇥 𑇦 𑇧 𑇨 𑇩 𑇪 𑇫 𑇬 𑇭 𑇮 𑇯 𑇰 𑇱 𑇲 𑇳 𑇴 |
1699 18th century
|
| Pentadic runes | 10 | 1800 19th century
| |
| Cherokee numerals | 10 | 1820 19th century (1820s)
| |
| Vai numerals | 10 | ꘠ ꘡ ꘢ ꘣ ꘤ ꘥ ꘦ ꘧ ꘨ ꘩ [9] | 1832 19th century (1832)[10]
|
| Bamum numerals | 10 | ꛯ ꛦ ꛧ ꛨ ꛩ ꛪ ꛫ ꛬ ꛭ ꛮ [11] | 1896 19th century (1896)[10]
|
| Mende Kikakui numerals | 10 | 𞣏 𞣎 𞣍 𞣌 𞣋 𞣊 𞣉 𞣈 𞣇 [12] | 1896 20th century (1917)[13]
|
| Osmanya numerals | 10 | 𐒠 𐒡 𐒢 𐒣 𐒤 𐒥 𐒦 𐒧 𐒨 𐒩 | 1921 20th century (1920s)
|
| Medefaidrin numerals | 20 | 𖺀 𖺁/𖺔 𖺂/𖺕 𖺃/𖺖 𖺄 𖺅 𖺆 𖺇 𖺈 𖺉 𖺊 𖺋 𖺌 𖺍 𖺎 𖺏 𖺐 𖺑 𖺒 𖺓 [14] | 1930 20th century (1930s)[15]
|
| N'Ko numerals | 10 | ߉ ߈ ߇ ߆ ߅ ߄ ߃ ߂ ߁ ߀ [16] | 1949 20th century (1949)[17]
|
| Hmong numerals | 10 | 𖭐 𖭑 𖭒 𖭓 𖭔 𖭕 𖭖 𖭗 𖭘 𖭑𖭐 | 1959 20th century (1959)
|
| Garay numerals | 10 | Garay numbers[18] | 1961 20th century (1961)[19]
|
| Adlam numerals | 10 | 𞥙 𞥘 𞥗 𞥖 𞥕 𞥔 𞥓 𞥒 𞥑 𞥐 [20] | 1989 20th century (1989)[21]
|
| Kaktovik numerals | 5&20 | Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit Template:Kaktovik digit 𝋀 𝋁 𝋂 𝋃 𝋄 𝋅 𝋆 𝋇 𝋈 𝋉 𝋊 𝋋 𝋌 𝋍 𝋎 𝋏 𝋐 𝋑 𝋒 𝋓 [22] |
1994 20th century (1994)[23]
|
| Sundanese numerals | 10 | ᮰ ᮱ ᮲ ᮳ ᮴ ᮵ ᮶ ᮷ ᮸ ᮹ | 20th century (1996)[24] |
Numeral systems are classified here as to whether they use positional notation (also known as place-value notation), and further categorized by radix or base.

The common names are derived somewhat arbitrarily from a mix of Latin and Greek, in some cases including roots from both languages within a single name.[25] There have been some proposals for standardisation.[26]
| Base | Name | Usage |
|---|---|---|
| 2 | Binary | Digital computing, imperial and customary volume (bushel-kenning-peck-gallon-pottle-quart-pint-cup-gill-jack-fluid ounce-tablespoon) |
| 3 | Ternary, trinary[27] | Cantor set (all points in [0,1] that can be represented in ternary with no 1s); counting Tasbih in Islam; hand-foot-yard and teaspoon-tablespoon-shot measurement systems; most economical integer base |
| 4 | Quaternary | Chumashan languages and Kharosthi numerals |
| 5 | Quinary | Aneityum (traditional),[28] Ateso, Gumatj, Kuurn Kopan Noot, and Nunggubuyu, Saraveca languages; common count grouping e.g. tally marks |
| 6 | Senary, seximal | Diceware, Ndom, Kanum, and Proto-Uralic language (suspected) |
| 7 | Septimal, septenary | |
| 8 | Octal | Charles XII of Sweden, Unix-like permissions, Squawk codes, DEC PDP-11, Yuki, Pame, compact notation for binary numbers, Xiantian (I Ching, China) |
| 9 | Nonary, nonal | Compact notation for ternary |
| 10 | Decimal, denary | Most widely used by contemporary societies[29][30][31] |
| 11 | Undecimal, unodecimal, undenary | A base-11 number system was mistakenly attributed to the Māori (New Zealand) in the 19th century[32] and one was reported to be used by the Pangwa (Tanzania) in the 20th century,[33] but was not confirmed by later research and is believed to also be an error.[34] Briefly proposed during the French Revolution to settle a dispute between those proposing a shift to duodecimal and those who were content with decimal. Used as a check digit in ISBN for 10-digit ISBNs. Applications in computer science and technology.[35][36][37] |
| 12 | Duodecimal, dozenal | Languages in the Nigerian Middle Belt Janji, Gbiri-Niragu, Piti, and the Nimbia dialect of Gwandara; Chepang language of Nepal, and the Mahl dialect of Maldivian; dozen-gross-great gross counting; 12-hour clock and months timekeeping; years of Chinese zodiac; foot and inch; Roman fractions. |
| 13 | Tredecimal, tridecimal[38][39] | Conway's base 13 function. |
| 14 | Quattuordecimal, quadrodecimal[38][39] | Programming for the HP 9100A/B calculator[40] and image processing applications.[41] |
| 15 | Quindecimal, pentadecimal[42][39] | Telephony routing over IP, and the Huli language.[34] |
| 16 | Hexadecimal, sexadecimal, sedecimal | Compact notation for binary data; tonal system of Nystrom. |
| 17 | Heptadecimal, septendecimal[42][39] | |
| 18 | Octodecimal[42][39] | |
| 19 | Undevicesimal, nonadecimal[42][39] | |
| 20 | Vigesimal | Basque, Celtic, Muisca, Inuit, Yoruba, Tlingit, and Dzongkha numerals; Santali, and Ainu languages. |
| 5&20 | Quinary-vigesimal[43][44][45] | Greenlandic, Iñupiaq, Kaktovik, Maya, Nunivak Cupʼig, and Yupʼik numerals – "wide-spread... in the whole territory from Alaska along the Pacific Coast to the Orinoco and the Amazon"[43] |
| 21 | The smallest base in which all fractions 1/2 to 1/18 have periods of 4 or shorter. | |
| 24 | Quadravigesimal[46] | 24-hour clock timekeeping; Greek alphabet; Kaugel language. |
| 25 | Sometimes used as compact notation for quinary. | |
| 26 | Hexavigesimal[46][47] | Sometimes used for encryption or ciphering,[48] using all letters in the English alphabet. Used to encode SHA-256 hashes into uppercase letters in InChIKey (a standard indexing system of chemical structures)[49] and SID (sequence identification, an indexing system of PCR amplicons in forensics).[47] |
| 27 | Telefol,[50] Oksapmin,[51] Wambon,[52] and Hewa[53] languages. Mapping the nonzero digits to the alphabet and zero to the space is occasionally used to provide checksums for alphabetic data such as personal names,[54] to provide a concise encoding of alphabetic strings,[55] or as the basis for a form of gematria.[56] Compact notation for ternary. | |
| 28 | Months timekeeping. | |
| 30 | The Natural Area Code, this is the smallest base such that all of 1/2 to 1/6 terminate, a number n is a regular number if and only if 1/n terminates in base 30. | |
| 32 | Duotrigesimal | Found in the Ngiti language. Also used to encode computer (binary) data into an alphanumerical string without confusable characters (e.g. zero and "O", eight and "B") in RFC 4648, with each character standing for 5 bits. |
| 34 | The smallest base where 1/2 terminates and all of 1/2 to 1/18 have periods of 4 or shorter. | |
| 36 | Hexatrigesimal[57][58] | Used to encode large numbers into an alphanumeric string (26 letters, 10 numbers). |
| 40 | DEC RADIX 50/MOD40 encoding used to compactly represent file names and other symbols on Digital Equipment Corporation computers. The character set is a subset of ASCII consisting of space, upper case letters, the punctuation marks "$", ".", and "%", and the numerals. | |
| 42 | Largest base for which all minimal primes are known. | |
| 47 | Smallest base for which no generalized Wieferich primes are known. | |
| 50 | SQUOZE encoding used to compactly represent file names and other symbols on some IBM computers. Encoding using all Gurmukhi characters plus the Gurmukhi digits. | |
| 60 | Sexagesimal | Babylonian numerals and Sumerian; degrees-minutes-seconds and hours-minutes-seconds measurement systems; Ekari; covers base 62 apart from I, O, and l, but including _(underscore).[59] |
| 64 | Used to encode computer (binary) data into a relatively compact string, with each character standing for 6 bits (RFC 4648). | |
| 72 | The smallest base greater than binary such that no three-digit narcissistic number exists. | |
| 80 | Used as a sub-base in Supyire. | |
| 89 | Largest base for which all left-truncatable primes are known. | |
| 90 | Related to Goormaghtigh conjecture for the generalized repunit numbers (111 in base 90 = 1111111111111 in base 2). | |
| 97 | Smallest base which is not perfect odd power (where generalized Wagstaff numbers can be factored algebraically) for which no generalized Wagstaff primes are known. | |
| 185 | Smallest base which is not a perfect power (where generalized repunits can be factored algebraically) for which no generalized repunit primes are known. | |
| 210 | Smallest base such that all fractions 1/2 to 1/10 terminate. |
| Base | Name | Usage |
|---|---|---|
| 1 | Unary (Bijective base‑1) | Tally marks, Counting. Unary numbering is used as part of some data compression algorithms such as Golomb coding. It also forms the basis for the Peano axioms for formalizing arithmetic within mathematical logic. A form of unary notation called Church encoding is used to represent numbers within lambda calculus.
Some email spam filters tag messages with a number of asterisks in an e-mail header such as X-Spam-Bar or X-SPAM-LEVEL. The larger the number, the more likely the email is considered spam. |
| 10 | Bijective base-10 | To avoid zero |
| 26 | Bijective base-26 | Spreadsheet column numeration. Also used by John Nash as part of his obsession with numerology and the uncovering of "hidden" messages.[60] |
| Base | Name | Usage |
|---|---|---|
| 2 | Balanced binary (Non-adjacent form) | |
| 3 | Balanced ternary | Ternary computers |
| 4 | Balanced quaternary | |
| 5 | Balanced quinary | |
| 6 | Balanced senary | |
| 7 | Balanced septenary | |
| 8 | Balanced octal | |
| 9 | Balanced nonary | |
| 10 | Balanced decimal | John Colson Augustin Cauchy |
| 11 | Balanced undecimal | |
| 12 | Balanced duodecimal |
| Base | Name | Usage |
|---|---|---|
| 2i | Quater-imaginary base | related to base −4 and base 16 |
| Base | related to base −2 and base 4 | |
| Base | related to base 2 | |
| Base | related to base 8 | |
| Base | related to base 2 | |
| −1 ± i | Twindragon base | Twindragon fractal shape, related to base −4 and base 16 |
| 1 ± i | Negatwindragon base | related to base −4 and base 16 |
| Base | Name | Usage |
|---|---|---|
| Base | a rational non-integer base | |
| Base | related to duodecimal | |
| Base | related to decimal | |
| Base | related to base 2 | |
| Base | related to base 3 | |
| Base | ||
| Base | ||
| Base | usage in 12-tone equal temperament musical system | |
| Base | ||
| Base | a negative rational non-integer base | |
| Base | a negative non-integer base, related to base 2 | |
| Base | related to decimal | |
| Base | related to duodecimal | |
| φ | Golden ratio base | early Beta encoder[61] |
| ρ | Plastic number base | |
| ψ | Supergolden ratio base | |
| Silver ratio base | ||
| π | Base | |
| eπ | Base | |
| Base |
| Base | Name | Usage |
|---|---|---|
| 2 | Dyadic number | |
| 3 | Triadic number | |
| 4 | Tetradic number | the same as dyadic number |
| 5 | Pentadic number | |
| 6 | Hexadic number | not a field |
| 7 | Heptadic number | |
| 8 | Octadic number | the same as dyadic number |
| 9 | Enneadic number | the same as triadic number |
| 10 | Decadic number | not a field |
| 11 | Hendecadic number | |
| 12 | Dodecadic number | not a field |
All known numeral systems developed before the Babylonian numerals are non-positional,[62] as are many developed later, such as the Roman numerals. The French Cistercian monks created their own numeral system.
<ref> tag; no text was provided for refs named Laycock 1975 219–233