数词

数词数词分基数词和序数词两类。一、数词的分类1.基数A．从1——10one，two，three，four，five，six，seven，eight，nine，ten．B．从11——19eleven，twelve，thirteen，fourteen，fifteen，sixteen，seventeen，eighteen，nineteen．C．从20——90特殊:twenty，thirty,forty，fifty，eighty21twenty-oneD．百位数101ahundredandone个数基数词后加hundred，表示几百;在几十几与百位间加上and．(200twohundred101a/onehundredandone,320threehundredandtwenty,648sixhundredandforty-eight)E．千位数以上thousandmillion百万billion十亿•从数字的右端向左端数起，每三位数加一个逗号“，”。从右开始，•第一个“，”前的数字后添加thousand，第二个“，”前面的数字后添加million，第三个“，”前的数字后添加billion,然后一节一节分别表示。2,648twothousandsixhundredandforty-eight16,250,064sixteenmilliontwohundredandfiftythousandsixty-four5,237,166,234fivebillion，twohundredandthirty-sevenmillion，onehundredandsixty-sixthousand，twohundredandthirty-four•intwosandthrees三三两两；零零星星•Theyarrivedintwosandthrees.•sixesandsevens乱七八糟，没有头绪•Theboymadetheroomatsixesandsevens.三、数词的用法1.hundred,thousand,million,billion这几个数词前如有具体数字，要用单数形式，后面加可数名词复数。twohundredstudentssixthoundpeople•2.如果hundred,thousand,million,billion•这几个数词前没有具体数字，应在四个词后•加s+of+可数名词复数；•数词与名词合成形容词时，四个单词用单数形式。•millionsoftrees•aten-thousand-wordstory•an11-year-oldboy3.several,some,many等词被认为是具体数字，其后跟hundred,thousand,million,billion的单数＋名词复数。Severalhundredsoldiersarecoming.4.anumberof+名词复数，许多，大量。谓语用复数；Anumberofstudentswereabsentfromthemeeting.thenumberof+名词复数，......的数目。谓语用单数。Thenumberofstudentsabsentfromthemeetingwasincreasing.5.用数词表示事物的编号。名词＋基数词＝the+序数词＋名词。Room8=theeighthroom6.用数词表示人的不确切岁数或年代，用几十的复数形式表示。Hebecameateacherinhisthirties.inthe1990s7.分数（是由基数词和序数词一起来表示的）。分子基，分母序，分子大于“１”分母用复数当分数作主语，谓语要根据分数后的名词确定单复数，如果是可数名词用复数，不可数名词用单数。OnethirdofthestudentsinourclasshavebeentoBeijing.Fourfifthsofthewaterisdrunkbythechildren.8.数词还可以用来表示时间、年月日等。注意：１）百分数由基数词＋percent来表示，percent不用复数形式９５％——ninety-fivepercent2)英语中表达“几个半”有两种方法：①“数词+andahalf+名词复数”；②“数词+名词复数+andahalf”。例如：twoandahalfhours/twohoursandahalf3）日期：May5五月五日（读作Mayfifth）,也可以表示为thefifth（5th）ofMay4）、时间表示法1.几点钟5:00读作fiveo’clock2.几点过几分fivepastseven七点过五分halfpastsix六点半aquarterpasteight八点过一刻3.几点差几分tentoeight差十分八点aquartertotwelve差一刻十二点twentytosix差二十分六点序数词•表示顺序的词称为序数词。•1．第一至第十九特殊:first，second，third，fifth，eighth，ninth，twelfth•其他:添加“th”。如sixth、nineteenth2．从第二十至第九十九变y为i，再加“eth”构成。twenty——twentieththirty——thirtieth表示第几十几时，用几十的基数词+连字符“－”+个位序数词。thirty-first第三十一fifty-sixth第五十六seventy-third第七十三ninety-ninth第九十九口诀•基变序，有规律•123，特殊记，结尾字母tdd•Th,从4起，8去t,9减e,•F来把ve替，ty变成tie,后加th就可以•若是遇到几十几，只变个位就可以3．序数词的缩写形式:阿拉伯数字后加上th。irst—lstsecond—2ndthird—3rdfourth—4thtwentieth—20thtwenty-third—23rd4．序数词的句法功能序数词在句中可作主语、宾语、定语和表语。ThesecondiswhatIreallyneed．（作主语）Hechoosethesecond．（作宾语）Wearetocarryoutthefirstplan．（作定语）Sheisthesecondinourclass．（作表语）注：通常前面要加定冠词the；但出现不定冠词a或an时，则表示“再—”，“又—”。We'llgooveritasecondtime．（1）单纯的序号，可在基数词前加number,简写为No.。如：No.1第一号（2）事物名词的序号表达法有所不同：•①对于一些小序号可有序数词也可用基数词表达，形式分别为：the+序数词+名词；名词+基数词。如：第一次世界大战可以表示为theFirstWorldWar或WorldWarOne,Lesson8=theeighthlesson•②对于一些大序号我们通常只用一种表达法，即名词+数词。如：501号房间表示为Room501,538路公共汽车表示为Bus538。•③可用a/the+number+基数词+名词。如：aNo.5bus一辆五路公共汽车，theNo.8bus那辆8路公共汽车。序数加减乘除表示法•1.加用plus，and或add表示；等于用is，make，equal等词表示。2+3=?可表示为：Howmuchistwoplusthree?2+3=5Twoplusthreeisfive．Twoandthreeisequaltofive．Twoandthreemakefive．Twoaddedtothreeequalsfive．Ifweaddtwoto/andthree,wegetfive•2.减用minus或takefrom表示10－6＝?Howmuchistenminussix?10-6=4Tenminussixisfour．Takesixfromtenandtheremainderisfour.Six(taken)fromtenisfour．十减去六等于四•3.“乘”用time（动词）或multiply表示3X4＝?Howmuchisthreetimesfour?3X4=12Threetimesfouris/aretwelve．Threefoursis/aretwelve．Multiplythreebyfour，andwegettwelve．Threemultipliedbyfourmakestwelve．三乘以四等于十二•4.“除”用divide的过去分词形式表示16÷4=?Howmuchissixteendividedbyfour?16÷4＝4Sixteendividedbyfourisfour．Sixteendividedbyfourequals/gives/makesfour．Ifyoudivide16by4,youget4.十六除以四等于四。总结、加减乘除表示法1.“加”用plus，and或add表示Howmuchistwoplusthree?Itisfive．Twoandthreeis/equalsfive．2.“减”用minusHowmuchistenminussix?3.“乘”multiply3X4＝?Howmuchisthreetimesfour?4.“除”用divide的过去分词形式表示16÷4=?Howmuchissixteendividedbyfour?分数的其它表达形式：•分子与分母之间加in,分子在前，分母在后，分子分母都用基数词。•如：oneinten十分之一，fiveineight八分之五。•分子与分母之间加outof,分子在前，分母在后，分子分母都用基数词。如：oneoutoften十分之一，fiveoutofeight八分之五选择填空。1．Marchis____monthofayear．A．athreeB．thethirdC．athird2．Wewillhaveameetingat8:05____．A．fivetoeightB．eightfiveC．eightofive3．Eightpluseightis____.A．sixteenB．sixty-fourC．one4．Heisan____boy．A．eightyearsB．eight-year-oldC．eight-years-old5．Wewillhavea___walk．A．tenminutesB．tenminutes'C．ten-minutesB．thethirdC．eightofiveA．sixteenB．eight-year-oldB．tenminutes'6．Thewallis____.A．fourmeterslongB．fourmeterlongC．four-meterlong7．What'sthedatetoday?It's___．A．MarchtheeightB．MarcheighthC．eight，March8．Ithappenedinthe1040's．A．inthefortiesoftheeleventhcentury．B．inthefortiesofthetenthcentury．C．intheforty9．About_____________oftheearth\'ssurfaceiscoveredwithwater.A.threefoursB.threefourthC.three-fourthsA．fourmeterslongB．MarcheighthA．inthefortiesoftheeleventhcentury．C.threefourths10.Hewentdowntothevillagewhichwas___milesawayfromthecity.A.threehundredsB.threehundredC.threehundredsofB.threehundred1._____peopleintheworldaresendinginformationbyE-maileveryday.A.SeveralmillionB.ManymillionsC.S