数词1、分类：数词有基数词和序数词两种。
英语的数词可以作句子的主语、宾语、表语和定语。
2、基数词：表示数目的词叫基数词。
1、英语中常用的基数词有：1 2 3 4 5 6 7 8 9 10 11 12onetwothreefourfivesixseveneightnineteneleventwelve13141516171819thirteenfourteenfifteensixteenseventeeneighteennineteen2030405060708090100twentythirtyfortyfiftysixtyseventyeightyninetyone(a) hundred2335101twenty-threethirty-fiveone hundred and one1000→one(a) thousand,10000→ten thousand,100000→one hundredthousand ,1000000→one million,10000000→ten million,100000000→one hundredmillion,108→one hundred and eight, 146→one hundred and forty-six, 500→five hundred , 1001→one thousand and one, 1813→one thousand eight hundred and thirteen.2、[注]：(1)百位与十位之间要加and；十万位和万位,亿位和千万位之间通常也要加and。
(2)英语用千、百万等单位计数,大数字从右向左看,每隔三位划一逗号,倒数第一个逗号之前要用thousand,倒数第二个逗号之前要用million,倒数第三的逗号之前要用billion表示。
(3) hundred、thousand、million作数词时,不用复数,前面可以加上one, two, …等其它数词。
用作名词时复数表示“成…上…”,后面必须要有of,前面可以加上some,many,several等词。
如：five hundred(五百),hundreds of(成百上千的),tenthousand(一万),thousands of(成千上万的),millions of(成百万的)3、序数词：表示顺序的数词叫序数词。
1、英语的序数词基本变法：(1) 一般在基数词后加th,(2)-ve结尾的改为-fth,(3)-ty结尾的改为-tieth,(4)熟记特殊词。
2、序数词如下：1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th ※first※second※thirdfourthfifthsixthseventheighthninthtentheleventhtwelfth13th14th15th16th17th18th19ththirteenthfourteenthfifteenthsixteenthseventeentheighteenthnineteenth20th30th40th50th60th70th80th90th100thtwentieththirtiethfortiethfiftiethsixtiethseventietheightiethninetiethone hundred21st22nd23rd35th101sttwenty-firsttwenty-secondtwenty-th irdthirty-fi fthone hundred andfirst1000th→one thousandth, 1000000th→one millionth., 第703→the seven hundredand third,第5480→the five thousand four hundred and eightieth.注：(1)两位以上的序数词仅个位数部分用序数词,其余部分仍用基数词。
如：thirty-sixth,(2) 使用序数词时一般加定冠词the.如：I’m in the third grade.(3) 序数词作“几分之几”讲时,有复数形式。
如：1/5→one fifth ; 2/3→two thirds ;4/7→four sevenths ; 1/2→a half ; 1/4→a quarter ; 3/4→three quarters ; 50%→fifty hundredths ( fifty per cent).4、数词的用法：1、表示年份：2002:twenty thousand and two ; 1976 : nineteen seventy-six.2、表示日期： 12月1日:Dec.1st或the first of December；2002年11月8日: Nov. 8th,20023、表示时刻：5：15→five fifteen或a quarter past five ; 8：30→eight thirty或halfpast eight ; 10：45→ten forty-five或a quarter to eleven.4、表示编号：Room 105→Room one 0 five; Bus No.13→Bus Number Thirteen; P.5→Page Five; Tel.No.7658659→Telephone Number seven-six-five-eight-six-five-nine5、小数的读法：5.7→five point seven, 0.16 →zero point one six.6、“半”的表达： 1/2→half, 半小时→half an hour, 1.5小时→one and a half hours或one hour and a half.7、序数词前面加the时,表示顺序,加a/an时表示“再一、又一”。
如：The third lessonis rather difficult.(第三课相当难)/ Shall we read the text a third time?(我们把课文读第三遍,好吗？)数词跟踪练习题1．Tom's cousin lives on the ____ floor.A．two B．twice C．twos D．second2．The boy got a nice present on his ____ birthday.A．nine B．ninthC．the nine D．the ninth3．Please turn to Page____and read the ______story.(2014，兰州)A．Ten；two B．Ten；secondC．Tenth；two D．Tenth；second4．Last year，Jimmy had his ____ vacation in Sanya.A．ten day B．ten day'sC．tenday D．tendays5．____ trees have been planted since 2011 in our town.A．Two hundreds B．Hundred ofC．Hundreds of D．Hundreds6．—Which is the smallest number of the four?—____.A．A half B．One thirdC．A quarter D．Two thirds7．About ____of the students like keeping diaries in English in our class.(2014，云南) A．two fifth B．two fifthsC．second five D．two five8．The machine was invented in ____ century.A．18th B．the 18thC．18 D．the 189．—Were Jack and Jerry born in the ____？—Yes，they were both born in ______.A．1995；1990s B．1995；1995C．1990s；1995 D．1990s；1990s10．—What are we going to learn?—____.A．8 Lesson B．the 8 LessonC．Lesson 8 D．the Lesson 811．—How often do you practice the piano?—____ a week.A．Two B．TwiceC．Second D．The second12．Time is not enough for so much work.____ people are needed，I think. A．Other two B．Only twoC．Two more D．Two others13．This new kind of material is ____ lighter than the old one.A．three times B．third timeC．three time D．third times14．—How deep is the hole?—It is ____.A．four meter deep B．four meters' deepC．four meter's deep D．four meters deep15．The ____ boy can sing this English song very well.A．ten year old B．ten years oldC．tenyearold D．tenyearsold16．—How many workers are there in that small factory?—____.A．Twenty nine B．Thirty and twoC．Fifties D．Fortyfive17．The scientist still works hard though he is ____.A．in his sixty B．in his sixtiesC．in sixties D．in the sixty18．Our school is not very big.There are only ____ students in it.A．nine hundred B．nine hundreds ofC．nine hundreds D．nine hundred of19．—How many new words are there in ____ lesson?—There are only ______.A．five；fifth B．fifth；the fifthC．the five；the five D．the fifth；five20．____ of the snacks on the table ______ for kids.A．Two third；is B．Two thirds；areC．Two thirds；is D．Two third；are21．Three hundred thousand one hundred and seventy means____.A．3，170 B．3，117 C．300，170 D．30，17022．—Is this your____visit to Zhengzhou?—No，I have been there for many times.A．one B．the first C．once D．first23．—If a＝4，b＝5，what's the answer to the question“a＋2ab＋1＝？”—____.A．FortyfifthB．FortyfiveC．TwentythreeD．One hundred and twenty one数词1-5 DBBCC 6-10 CBBCC 11-15 BCADC 16-20 DBADB 21-23 CDB。