數字字首  是派生於數詞或其他數字的字首。在英語和其他歐洲語言，這些字首用來造一系列包含表示數量資訊的詞。 例子 數字字首有拉丁語、希臘語、梵語三種，但主要使用前兩者。 具體例子如下： 單詞：bicycle（兩個輪子；腳踏車）、sextet（六重唱）、octopus（八隻腳；章魚）、decade（十年）、octave（八度） 數學術語：triangle（三角形）、quadruple（四倍）、quaternion（四元數）、pentagon（五邊形）、regular dodecahedron（正十二面體） 進位制：binary（二進位制）、decimal（十進位制）、sexagesimal（六十進位制） 西方的數字命名法：billion 原意為 106 2、trillion 原意為 106 3、quadrillion 原意為 106 4 表示分子結構的字首：octane（辛 八碳 烷）、pentane（戊 五碳 烷） 國際單位制中的國際單位制詞頭：deca（十）、deci（分）、centi（釐） 英語中的數字字首表 希臘語及拉丁語中，數分四種： 基數：如英語中的 one、two、three、four、five 等 次數（或）：once、twice、thrice 等 分配數：漢語中的「各～個」。原本指意味著 one each、two each，但在現代常常會失去這個意思。 序數 ：漢語中的「第～個」，如英語的 first、second、third、fourth、fifth 等。也兼備分數，表示「N 分之一」，但 12 有特殊形式。 對於百位數，有來自拉丁語的 gent，以及加上為 19 的字首的 cent 兩種。 數 拉丁語字首 拉丁語字首 拉丁語字首 拉丁語字首 希臘語字首 希臘語字首 希臘語字首 梵語字首 See Mendeleevs predicted elements for the most common use of Sanskrit numerical prefixes 數 基數 次數 分配數 序數 基數 次數 序數 梵語字首 See Mendeleevs predicted elements for the most common use of Sanskrit numerical prefixes 0 nulli nulli nulli meden ouden unci unci unci 對於分數希臘人使用序數表示 ie dodecato 對於分數希臘人使用序數表示 ie dodecato 對於分數希臘人使用序數表示 ie dodecato octant 如上，ogdoö 如上，ogdoö 如上，ogdoö sextant 如上，hecto 如上，hecto 如上，hecto quadrant 如上，tetarto 如上，tetarto 如上，tetarto trient 如上，trito 如上，trito 如上，trito semi demiDemi is French from Latin dimidium hemi mn half eg hemisphere dodrant 1 uni eg universe unilateral simsim sin is found in the words simplex simple singul prim mono 一 單eg monogamy holo 整個 完整 eg holocaust holographyhenThe Greek prefix for one is normally mono alone Hen one is only used in compound numbers hendeka 11 and a few words like henad monad Haplo single is found is a few technical words such as haploid 罕見 mono 一，單 hapax 單次 haplo 單倍 monad 單位 單元 prot eg proton protozoa eka quasquiquasquicentennial sesquieg sesquicentennial sesquipedalian 2 du bi bis bireme bilingual bipolar bipartisan bin second di dy duodyo dis 兩次 常見 dyakis 兩次 罕見 diplo 雙倍 dyad 一對 deuter eg Deuteronium Deuteronomydeuteraio每隔一天 dvi 3 tri eg trireme ter tern trin terti tri eg triathlon Tripolis tris 三次 常見 triakis 三次 罕見 triplo 三倍 triad 三個一組 trit 第三 eg Tritoniumtritaio 每隔兩天 tri 4 quadriquadruThe forms related to quattuor four like the previous three integers are irregular in Latin and other IndoEuropean languages and the details while presumably a form of assimilation are unclear Andrew Sihler New comparative grammar of Greek and Latin p 412 and Carl Darling Buck Comparative grammar of Greek and Latin In particular quadri has the alternate form quadru before p in some Latin words such as quadruple quater quatern quart tetratessara tetrakis四次 tetraplo 四倍 tetrad 四個一組 eg tetrahedron tetarto 第四 tetartaio 每隔三天 chatur 5 quinque quin quint penta pentakis pentaplo pentad eg pentahedron pemptpemptaio pancha 6 sexaSometimes Greek hexa is used in Latin compounds such as hexadecimal due to taboo avoidance with the English word sex sen sext hexa hexakis hexaplo hexad eg hexahedron hect hectaio shat 7 septemsepti septemsepti septen septim hepta eg heptathlon heptakis heptaplo heptad hebdomo 第七 hebdomaio每隔六天 hebdomas 一週 sapta 8 octo eg October octon octav octo eg octopus octakis octaplo octad eg octahedron ogdoö ogdoaio ashta 9 novem eg November novem eg November noven nona ennea enneakisenneaploennead enat enataio navam 10 decem dec decem dec den decim deca eg decathlon Decapolis decakisplod eg decahedron decagon decatdecataio dasham 11 undec undec unden undecim hendeca hendecakisplod hendecatoaio ekadasham 12 duodec duodec duoden eg duodenum duodecim dodeca eg dodecadactylum dodecakisplod eg dodecahedron dodacatoaio dvadasham 13 tredec tredec treden tredecim tria kai decadecatria eg triskaidekaphobia tris kai decakisdecatriakisplod decatotrito etc trayodasham 14 quattuordec quattuordec quattuorden quattuordecim tessara kai decadecatettaradecatessara tetra kai decakisdecatetrakisplod eg tetradecahedrondecatetrahedron decatotetarto chaturdasham 15 quinquadec quindec quinquadec quindec quinden quindecim pente kai decadecapente penta kai decakisdecapentakis etc decatopempto panchadasham 16 sedecsexdec 但是有混種詞 hexadecimal sedecsexdec 但是有混種詞 hexadecimal seden sedecim hexa kai decahekkaidecadecahex hexa kai decakis decahexakis etc decatohecto shodasham 17 septendec septendec septenden septendecim hepta kai decadecahepta hepta kai decakisdecaheptakis etc decatohebdomo saptadasham 18 octodec octodec octoden octodecim octo kai decadecaocto octa kai decakisdecaoctakis etc decatoogdoö ashtadasham 19 novemdecnovendec novemdecnovendec novemden novemdecim ennea kai deca decaennea ennea kai decakisdecaenneakis etc decatoenato navadasham 20 viginti viginti vicenvigen vigesim e icosi eicosakisplod eg e icosahedron eicosto vimshati 22 duovigint duovigint duovigint duovigint e icosidyodyo e icosi rare eg docosahexaenoic acid a pejoration of dyoicosahexanoic e icosidyakis e icosidiplo e icosidyad eicostodeutero 24 quattuorvigint quattuorvigint quattuorvigint quattuorvigint e icositettarae icosikaitettara rare e icositetrakis e icositetraplo e icositetrad eg e icositetragon eicostotetarto chaturvimshati 25 quinvigint quinvigint quinvigint quinvigint e icosipente eg eicosapentaenoic acid e icosipentakis e icosipentaplo e icosipentad eicostopempto 30 triginti triginti tricen trigesim triaconta triacontakis etc eg triacontahedron triacosto trimshat 31 untriginti untriginti untriginti untriginti triacontahen triacontahenakis triacontahenaplo triacontahenad triacostoproto triacostoprotaio 40 quadraginti quadraginti quadragen quadragesim tettaracontatessaraconta tettaracontakistessaracontakis etc tessaracosto chatvarimshat 50 quinquaginti quinquaginti quinquagen quinquagesim penteconta eg penteconter pentecontakis etc pentecosto eg pentecost panchashat 60 sexaginti sexaginti sexagen sexagesim hexeconta hexecontakis etc hexecosto shasti 70 septuaginti eg Septuagint septuaginti eg Septuagint septuagen septuagesim hebdomeconta hebdomecontakis etc hebdomecosto saptati 80 octogint octogint octogen octogesim ogdoëconta ogdoëcontakis etc ogdoëcosto ashiti 90 nonagint nonagint nonagen nonagesim eneneconta enenecontakis etc enenecosto navati 100 centi centi centen centesim hecato n hecatontakishundred timeshecatontaplohundredmultiplehecatontadhundred of a kindalso abbreviated inhec aton tad hecatostohundredthhecatostaiothe hundredth day shata 120 viginticenti viginticenti hecaton e icosi hecaton e icosakis etc hecatostoeicosto 200 ducenti ducenti ducenbicenten ducentesim diacosia diacosakis etc diacosiosto 300 trecenti trecenti trecentercententricenten trecentesim triacosia etc triacosakis triacosaplo triacosad triacosiosto 400 quadringenti quadringenti quadringenquatercentenquadricenten quadringentesim tetracosia tetracosakis etc tetracosiosto 500 quingentquincent quingentquincent quingenquingentenquincenten quingentesim pentacosia pentacosakis etc pentacosiosto 600 sescenti sexcenti sescenti sexcenti sescensexcenten sescentesim hexacosia hexacosakis etc hexacosiosto 700 septingenti septingenti septingenseptingentenseptcenten septingentesim heptacosia heptacosakis etc heptacosiosto 800 octingenti octingenti octingenoctingentenoctocenten octingentesim octacosia octacosakis etc octacosiosto 900 nongenti nongenti nongen nongentesim ennacosiderived fromen n iacosiaa pejoration ofenneacosia enneacosakis etc enacosiostalt spellingen n iacosiost o a pejoration ofenneacosiosto 1000 milli milli millen millesim chilikilo chiliakis chiliaplo chiliad chiliost sahasra 2000 duomilli duomilli dischili dischiliakis etc dischiliosto 3000 tremilli tremilli tremilli tremilli trischili trischiliost 5000 quinmilli quinmilli quinmilli quinmilli pentacischili decamilli decamilli decamilli decamilli myria eg myriapoda decakischilia myriakis myriaplo myriaddecakischiliakis etc myriastdecakischiliosto ayuta octogintmilli octogintmilli octogintmilli octogintmilli octacismyri centimilli centimilli centimilli centimilli decakismyria hecatontakischilia decakismyriakishecatontakischiliakis etc million hecatommyria hecatommyriakis 十萬次 hecatommyriaplo十萬倍 hecatommyriad十萬個一組 hecatommyriosto第十萬；或十萬之一 hecatommyriostaio每隔九萬九千九百九十九天 billion dishecatommyria dishecatommyriakis etc trillion trishecatommyria trishecatommyriakis etc quadrillion tetrakishecatommyria tetrakishecatommyriakis etc quintillion sextillion septillion octillion nonillion decillion decakishecatommyria decakishecatommyriakis etc centillion hecatontakishecatommyria hecatontakishecatommyriakis etc chiliakishecatommyria chiliakishecatommyriakis etc myriakishecatommyria myriakishecatommyriakis etc decakismyriakishecatommyria and so on virtually endless decakismyriakishecatommyriakis etc 少量 120 pauci eg pauciparous pauci eg pauciparous pauci eg pauciparous oligo eg oligomer oligonucleotide oligopeptide oligosaccharide oligopoly 大量 1 multi eg multilingual multiple pluri eg plural wife pluralism multi eg multilingual multiple pluri eg plural wife pluralism multi eg multilingual multiple pluri eg plural wife pluralism poly eg polyhedra polygamy polypod polyglot polymath pollakis 多次 pollaplo 多次 plethos plethora 多個為一組 pollosto 次序中排在第一後的， 即序數大於 1 bahut 補充 母音脫落：數字字首結尾的母音會在以母音為開頭的詞幹前脫落。但除了 bi 其在母音前為 bis 而其他單音節字首 du、di、dvi、tri 即使接以母音為開頭的詞幹也保持不變。 連字元：數字字首不加入連字元的情況比較多、但還是有把 quarterdeck 寫成 quarterdeck 的例外。在 IUPAC 命名法和國際單位制詞頭中不會加入連字元。 同樣的字尾可用於不同數： primary secondary tertiary quartary quintary sextary septimary octavary nonary decimary singulary binary ternary trinary quaternary quinary senary septenary octonary nonenary denary 在化學命名中，11（undeca）這個字首混合了拉丁語和希臘語，並以 cos 表示二十，例如 tricos 是 23。同樣，表示進位制的 binary trinary senary 和 octal decimal vigesimal 拉丁語基數詞 unicycle bicycle tricycle quadricycle uniped biped triped quadruped centipede millipede 拉丁語分配數詞 unary binary trinary quaternary quinary senary vicenary centenary denarian vicenarian tricenarian quadragenarian quinquagenarian sexagenarian septuagenarian octogenarian nonagenarian centenarian millenarian 希臘語 monad dyad triad tetrad pentad hexad heptad ogdoad ennead decad triacontad hecatontad chiliad myriad digon trigon tetragon pentagon hexagon heptagon octagon enneagon decagon hendecagon dodecagon enneadecagon icosagon triacontagon chiliagon myriagon trilogy tetralogy pentalogy hexalogy heptalogy monopod dipod tripod tetrapod hexapod octopod decapod 混合語言 戊烷，己烷，庚，辛烷，壬，In organic chemistry most prefixes are Greek but the prefixes for 9 and 11 are Latin 癸烷，一烷， 二十烷 參見 IUPAC 數值字首 數表 十進位制 科學命名常用字尾列表 數詞 註釋 參考文獻 Oxford English Dictionary 2nd edition Buck Carl Darling Comparative Grammar of Greek and Latin Sihler Andrew Littleton A New Comparative Grammar of Greek and Latin Oxford University Press 1995 外部連結 Category 數字 Category 字首 Category 古希臘語 Category 拉丁語 Category 梵語 Category 英語