数词讲解专项练习1数词的讲解一、定义:表示数目或顺序二、分类:分为基数词和序数词两种。表示数目或数量多少的词叫基数词;表示数目顺序的词叫序数词。三、基数词的构成:1)1-12的基数词是独立的单词,即:one,two,three,four,five,six,seven,eight,nine,ten,eleven,twelve。2)13-19的基数词以-teen结尾。如:fourteen,seventeen等,但13,15,18较特殊,13—thirteen,15—fifteen,18—eighteen。3)20-90的整十位均以-ty结尾。如:sixty,ninety,但20,30,40,50,80较特殊,20—twenty,30—thirty,40—forty,50—fifty,80—eighty。4)十位数与个位数之间要加连字符号-,如:28-twenty-eight,96-ninety-six。5)百位和十位(若无十位则和个位)之间加and,如:148—onehundredandforty-eight406—fourhundredandsix6)hundred(百),thousand(千),million(百万),billion(十亿)等前面即使有具体的数词,several,some,many也不能在它们的后面加-s。如:sixhundred,eightmillion。如果表示不确定数目时,用hundredsof/thousandsof/millionsof/billionsof+名词复数,前面不能再加数字。7)1000以上的数字,从后往前数每三位加一个逗号,第一个逗号前为千(thousand),第二个逗号前为百万(million),第三个逗号前为billion(十亿)。英语中无“万”这个词,我们可以用几十个千(thousand)表示几万,几百个千(thousand)表示几十万。如:2,510=twothousandfivehundredandten84,296=eighty-fourthousandtwohundredandninety-six274,350=twohundredandseventy-fourthousandthreehundredandfifty。四、序数词的构成:1)序数词一般是以与之相应的基数词尾加-th构成,如:fourth,tenth,但以下的这些基数词变为序数词时,有特别之处。One—first,two—second,three—third,five—fifth,nine—ninth,twelve—twelfth2)以_ty结尾的单词,要先变y为i,在加-eth.。如:thirty—thirtieth,fifty—fiftieth3)以one,two,three等结尾的多位数词,要将个位数变成序数词。如:twenty-one—twenty-first,onehundredandone—onehundredandfirst注意:序数词前常用定冠词,有时还可以用不定冠词a/an则表示又一的意思。(没有具体范围的限制)如:Mr.Brownhasasecondcar.布朗先生另外还有一辆车。Hehastriedasecondtime.他又尝试了一次。五、数词的应用1)时刻的表示:小时、点钟、分钟、秒钟要用基数词。①“几点钟”用基数词加o'clock。o'clock可省略。如:5点钟-five(o'clock)②“几点过几分”,≤30分钟用介词past。如:7:15—fifteen/aquarterpastseven7:30—halfpastseven③“差几分几点”用介词to。如:7:40—twentytoeight7:45—fifteen/aquartertoeight。④日常生活中的时间读法常常简化,直接按基数词的顺序读。如:7:05—sevenofive7:15—sevenfifteen。2)年月日的表示:①年份用基数词,如:1999年—nineteenninety-nine1900年—nineteenhundred2000年—twothousand1905年—nineteenofive;②年用基数词,日用序数词。如:1998年6月8日写作:June8,1998;读作:Junetheeighth,nineteenninety-eight或theeighthofJune,nineteenninety-eight。3)世纪、年代表示法,如:(在)90年代(in)thenineties(在)19世纪(in)thenineteenthcentury(在)18世纪30年代(in)the1730s或inthe1730's4)编号的表示:①基数词放到名词的后边,该名词一般要大写;序数词放到名词的前面,加定冠词。Lesson1/thefirstlesson第一课Row3/thethirdrow第三排②BusNo.3=theNo.3bus3路公共汽车。③表示住所时不用No.如:Room302读作:roomthreeotwo302房间。④如果编号的数词比较长,一般用基数词。如:Page457第457页。⑤电话号码,用基数词,如:3855633-threeeightdoublefivesixdoublethree。5)分数的表达:分子用基数词,分母用序数词,分子大于1,分母则加s。如:1/3onethird2/3twothirds1/2a/onehalf1/4onefourth或a/onequarter3/4threefourths或threequarters6)表示有小数的词用基数词,如:5.5fivepointfive12.135twelvepointonethreefive7)表示百分数,如:5℅:fivepercent0.8℅zeropointeightpercent注意:分数、百分数与主谓一致当分数、百分数修饰可数名词的复数时,谓语动词用复数形式;当分数、百分数修饰不可数名词时,谓语动词用单数形式。如:EightypercentofthestudentsinourschoolcomefromHenan.我们学校百分之八十的学生来自河南。ThreefourthsofthestudentsinmyclassareinterestedinEnglish.我们班四分之三的学生对英语感兴趣。Twothirdsofthewaterontheearthisseawater.地球上三分之二的水是海水。8)其他用法,如:①基数词+单数名词+形容词构成合成形容词。如:afive-year-oldboy一个五岁的男孩an800-metre-longbridge一座800米长的桥girls’400-metrerelayrace女子400米接力②具体数词+metre(s)/kilometre(s)/kilo(s)long/high/tall/deep/away等。如:TheChangjiangRiveris6,300kilometreslong.长江长6300公里。③表示“几十岁”用基数词的复数形式,如:inhisthirties在他三十几岁时④倍数的表达:一倍用once,两倍用twice,两倍以上用基数词+times。如:fivetimes5倍补充:倍数的表示法:1.表示“几倍大小(长短;数量)”,由“倍数+thesize(length,amountwidthageheight.)+of”结构组成。如:Theearthisforth-ninetimesthesizeofthemoon.地球的大小是月亮的四十九倍。2.表示“„„比„„大几倍”,由“倍数+形容词(副词)比较级+than+被比较部分”结构组成。如:Thisboxisthreetimesbiggerthanthatone.这个箱子比那个箱子大三倍。(这个箱子是那个箱子的四倍。)数词练习()1.Everyyear,_____peoplegotovisittheirfactoryA.athousandofBthousandsC.thousandofD.thousandsof()2.Tomhasjustfinishedwritinga_________article.A.nine-hundred-wordsB.nine-hundreds-wordC.nine-hundred-wordD.nine-hundreds-words()3._______peoplelosttheirhomesinJapan’searthquake.A.TwothousandsB.ThousandC.ThousandsofD.Thousandof()4.Lastyear,IvisitedachemicalfactoryinBaise,thereareabout_____workersinit.A.sixthousandsB.sixthousandC.sixthousandsofD.sixthousandof()5.About_______ofthestudentsinourclasswereborninthe_____.A.two-thirds,1990sB.two-thirds,1990C.two-third,1990sD.two-third,1990()6.NowadaysofbusinesslettersarewritteninEnglish.A.twothirdB.twothirdsC.twothreeC.secondthree()7.—Ifa=4,b=5,what’stheanswertothequestion“a+2ab+1=?”—A.Forty-fifthB.Forty-fiveC.Twenty-threeD.Onehundredandtwenty-one()8.—Howoftendoyouexercise?—_________aweek.A.TwoB.TwiceC.SecondD.Three()9.Theteachersaidthat__oftheboyswouldtakepartinthetalentshow.A.threefiveB.threefivesC.thirdsfifthsD.threefifths()10.Tomorrowistheboy’s________birthday.A.seventhB.sevenC.seventeenD.aseventh()11.—Whichisthebiggestnumberofthefour?—.A.One-thirdB.Two-thirdsC.AhalfD.Aquarter()12.—Excuseme,wherecanIbuyajacket?—YoucangototheMen'sWearSectiononthe_________floor.A.twoB.twiceC.secondD.three()13.___ofthelandiscoveredwithtreesandgrassinPingjiang,Yueyang.A.ThreefivesB.ThreefifthsC.ThreefifthD.Threesfifth()14.Septemberis_____monthoftheyear.A.ninthB.nineC.thenineD.theninth()15.—Howwasyourdayoffyesterday?—Perfect!Itwasmygrandma’s________birthday.Wehadabigcake.A.eightyB.eightiethC.theeightiethD.theeightieth()16.—Excuseme,howcanIgettothemuseum?—Sorry.It'smy______timetobehere.A.oneB.firstC.onceD.two()17.Youcansee_______ifyougooutatnight.A.millionstarsB.thousandofs