八上 U2 Numbers 语法（基数词，序数词）【学习目标】掌握基数词和序数词的用法及综合运用【课前小测】1. —Where were you born, Michael?—I was born in a small village with only three ______ people. hundred B. hundreds C. hundreds of 2. —Hi, Andy! There are ______ floors in this building. Which floor do you live on? —I live on the ______ floor. A. thirty; twenty-second B. thirty; twenty-two C. thirtieth; twenty-two3. Li Ming will be ____. His parents are going to have a party for his ____ birthday.A. sixteen; sixteenth B. sixteen; the sixteenth C. sixteen; sixteen4. —Welcome to Los Angeles. Have you ever been here?—Sure. I visited this city three years ago, so this is my ____ time here. A. first B. second C. third5 ____ Kobes fans watched his final match and ____ of them are men.A. Million of; three fourths B. Three million; third four C. Millions of; three fourths6. —Yan Jiashuo, a ____ girl, has won the prize of International Master Memory. —Wow, shes great, isnt she? A. ten-year-old B. ten-years-old C. ten years old【要点梳理】基数词与序数词1. 基数词表示数目多少的数词称为基数词，意思表示为“几、几个”其基本构成如下：1. 1~12 的英文表达没有规律可循，需要同学们逐个牢记。
2. 13~19 的英文表达由“ 个位数+ 后缀⁃teen”构成其中13(thirteen) ，15(fifteen)，18(eighteen)发生拼写变化3. 20~99 之间的整十的数，由“2~9+后缀⁃ty”构成其中20(twenty)，30(thirty)，40(forty)，50(fifty)，80(eighty) 发生拼写变化个位数不为零的两位数，在十位数与个位数中间加连字符“⁃”如：25(twenty⁃five)，34(thirty⁃four)4. 整百的数由“百位数+hundred”构成；非整百的三位数，在百位数与十/ 个位数中间要用and 连接如：325 （three hundred and twenty ⁃five）， 503(five hundred and three)5. 整千的数由“千位数+thousand”构成；非整千的四位数，由千位数直接加百、十、个位数构成如：2,138（two thousand one hundred and thirty⁃eight）6. hundred，thousand，million，billion 的前面有具体数字时不能用复数形式，但在表示不确切的数时，要用复数形式，后面要加of。
如：5,000（five thousand），数以百计的（hundreds of）7.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123456789101112onetwothreefourfivesixseveneightnineteneleventwelve13141516171819thirteenfourteenfifteensixteenseventeeneighteennineteen2030405060708090100twentythirtyfortyfiftysixtyseventyeightyninetyone(a) hundred2335101238twenty-threethirty-fiveone hundred and onetwo hundred and thirty-eight 2、序数词表示顺序先后的数词称为序数词，意思表示为“第几”其构成如下：1. 1~19除了first ( 第一)，second ( 第二) 和third (第三)为特殊变化外，其余均由“基数词+后缀⁃th”构成。
其中注意fifth(第五)，eighth (第八)，ninth (第九)，twelfth(第十二)的拼法变化2. 20~9920 以上的序数词，先将基数词词尾y 改成i，然后再加⁃eth如：twentieth(第二十)非整十的序数词，它的十位数为基数词，只将个位数变为序数词如：forty⁃first (第四十一)，fifty⁃second (第五十二)，ninety⁃sixth (第九十六)3. 100-999,1000-9999整百/ 千的序数词由“百/ 千位数+hundred / thousand / ...+后缀⁃th”构成，如：two hundredth (第二百)；非整百/ 千的数，末位数用序数词，前位数用基数词如：one hundred and thirty⁃eighth( 第一百三十八)，three hundred and third(第三百零三)基数词变序数词口诀: 基变序,有规律,词尾要加th .一二三,特殊记,词尾分别tdd (first second third ) 八去t ,九去e,ve要用f替.ty变作tie,再加th莫忘记. 若遇几十几,只变个位就可以.序数词如下：1st2nd3rd4th5th6th7th8th9th10th11th12thfirstsecondthirdfourthfifthsixthseventheighthninthtentheleventhtwelfth13th14th15th16th17th18th19ththirteenthfourteenthfifteenthsixteenthseventeentheighteenthnineteenth20th30th40th50th60th70th80th90th100thtwentieththirtiethfortiethfiftiethsixtiethseventietheightiethninetiethone hundredth21st22nd23rd35th101sttwenty-firsttwenty-secondtwenty-thirdthirty-fifthone hundred and first【拓展】 （1）序数词主要用作定语，通常在前面加定冠词the. 但当序数词前有形容词性物主代词或名词所有格修饰时，不用定冠词the。
Mr Lin lives on the fifth floor. Simon is his third child.(2)如果序数词前出现不定冠词，a 或 an 表示再，又 You’ll have to do it a second time.(3)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,(4)表示日期 Today is the fifth of March.今天是3月5日5）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 percent).分数作主语时, 谓语动词根据分数词后面的名词来确定. Two fifths of the milk ______(be ) drunk by Tom . One third of the students _______(be )girls .3、数词的用法：（1）表示年份： 结构: 1).月 日,年 (日用序数词,年用基数词) 注:年份的读法: 先读前两位数,再读后两位数. 读日时要加the.1900 --- nineteen hundred 1807--- onethousandeighthundredandseven2008 --- two thousand and eight 2).日 月 年 (the +序数词+of +月, 年)2007年3月21日---the twenty-first of March ,two thousand and seven. --- March the twenty-first ,two thousand and seven.2002: twenty thousand and two ; 1976 : nineteen seventy-six.12月1日: Dec.1st或the first of December；2002年11月8日: Nov. 8th, 2002.（3）表示时刻： 5：15→ five fifteen或a quarter past five ; 8：30→ eight thirty或half past eight ; 10：45→ ten forty-five或a quarter to eleven.（4）表示编号： 结构:名词(首字母要大写) + 基数词 = the +序数词 +名词 Lesson One = the first lesson 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-nine（5）小数的读法：5.7→ five point seven, 0.16 →z。