数词就是表示事物的数量和顺序的词， 分基数词和序数词两种。 表示数目或数量多少的词叫基数词， 如：one，ten, fifteen 等； 表示数目顺序的词叫序数词， 如：fifth, second, twelfth等。
one two three four five six seven eight nine ten eleven twelve
2）13--19, 由3－9 + teen构成。
14–fourteen 16--sixteen 17--seventeen 19—nineteen 特殊拼写: 13– thirteen 15--fifteen 18—eighteen
20—twenty 30—thirty 40—forty 50—fifty 80—eighty 60—sixty 70—seventy 90—ninety
4）21－99， 两位数，十位与个位之间有 “－”。
21 twenty-one 55 fifty-five 99 ninety-nine 5）101—999，三位数，百位与十位/个位之间加 and。 101 one hundred and one 840 eight hundred and forty 693 six hundred and ninety-three
40 50 1505 70
6) 1，000以上数目,从右向左每三位用“，” 分开,分别读为thousand , million, billion，
6 , 500 , 431 , 7 29
1、表示数量的多少。 There are 24 students in our class. 2、表示年份和年龄。 1）He was born in 1952. 2)—How old is Lily? --She is 15 years old. 3、表示顺序。 单数名词+基数词(名词和基数词首字母大写) =the+序数词+单数名词（名词的首字母不用大写） Class One 一班 Room 5 5号房间 Lesson Ten = the tenth lesson
4、表示时刻 (介词用at) What time is it? It’s…
1)顺读法----先时后分, ―几点几分” 9:30 nine thirty 6:21 six twenty-one 2)逆读法----先分后时 表示“几点过几分”，半小时以内，介词用past 分钟数+past +钟点数 10:10 ten past ten 8:20 twenty past eight 表示“几点差几分”，半小时以上，介词用to 60减原分钟+ to + (下一个)钟点数 9:50 ten to ten 7:40 twenty to eight 3) 15分钟：a quarter 30分钟：a half 9:15 a quarter past nine 12:30 half past twelve
What is the time?
six /six o’clock
four o five / five past four
seven fifteen /a quarter past seven
nine twenty / twenty past nine
nine thirty /half past nine
six forty /twenty to seven
表示具体数目,hundred, thousand, million不用复数。 表示不确定数目,用复数。即hundreds of(数百), thousands of(数千), millions of(数百万)+ 名词复数, 可以用many/several/some修饰，但不能与具体数目连用。
1) Our country has a population of 1,300 million people. 2) There are three thousand students in our school. 3) After the war, thousands of people became homeless. 4) Several / Many thousands of trees must be planted every year.
几十多岁 ---- in + one’s + 数词复数 年 代 ---- in + the +数词复数 1) He di
ed in his forties．四十多岁 2) In the nineties, most people go to work by bike.
7、“基数词+名词” 的合成形容词作定语， 中间有连字符“－”,当中的名词用单数。
a 3 – year – old girl a seven-day holiday
8、“another+基数词+名词复数”或“基数 +more+名词复数”表示在已有的基础上再增加一 定的数量。 1）He ate another two cakes.
(B ) 1. Last year girls took part in the competition but only a few of them succeeded. A. ten millions B. millions of C. ten million of D. ten millions of (A ) 2. — Can you write the number one million, seven hundred and fifty-five thousand, six hundred and forty-six? — Yes, it is . A. 1,755,646 B. 10, 755, 646 C. 17,055,646 D. 1,705,646
3.－How many people will come to Beijing next year? B －It’s hard to say, ________ people, I think. A.million of B. many millions of
C. three millions D. three millions of
1) 1－3, first, second, third 。 2) 4－19, 相应基数词+th, 特殊拼写:fifth, eighth, ninth, twelfth。
3) 20－90, y变成ie +th,如twentieth。
4) 21－99, 只把个位的基数词变成序数词 如twenty-first。 5) 序数词缩写—数字＋最后两字母 如1st, 2nd, 3rd ,4th…
基变序,有规律, 一、二、三，特别记，其余后加 th , 八减“t”，九去“e”， “f”要将“ve” 替，(five, twelve) 几十几要牢记，只变个位就可以。 遇到 ty 结尾时，“y”变“i”“e”，再加 “th”， (twenty, thirty,……ninety) 序数词缩写记清楚,数字后跟两字母。
The first truck is carrying a food basket．
John lives on the fifteenth floor．
注： She is my first English teacher.（当序数词与形容 词性物主代词、名词所有格连用时其前不用定冠词）
We‘ll have to do it a second time． Shall I ask him a third time？ They had a second child in 1988.
年用基数词表示,两位一读,介词用in 日用序数词表示,介词用on 1999 nineteen ninety-nine 2008 two thousand and eight 1949年10月1日 读作: October (the) first, nineteen forty-nine (月-日，年) the first of October, nineteen forty-nine（日-月，年） 写作: October 1st,1999(日用缩写，月-日-年) October 1, 1999 (日用数字) 1st October,1999日-月，年 表示“在…世纪”, 用序数词。 在20世纪 写作：in 20th century 读作：in the twentieth century
(B) 1. — How old is your son? — . We had a special party for his birthday last Sunday. A. Nine; nine B. Nine; ninth C. ninth; ninth D. Ninth; nine (B) 2. — Although you failed four times, I hope you can have try. — Thank you, I will. A. the fifth B. a fifth C. the fourth D. a fourth
(B) 3. — What is the date today? — It’s . A. Thursday B. June the s
ixteenth C. the best day D. Monday (B) 4. — When were you born in Shanghai? — . A. In January 1st, 1995 B. On January 1st, 1995 C. On 1995, January 1st D. In 1st January, 1995 (A) 5. He began to work there in his . A. fifties B. fifty C. fiftieth D. the fiftieth (B) 6. It’s ten to ten. We can also read it . A. nine fifteen B. nine fifty C. ten past ten D. ten ten
1/4 one-fourth 3/4 three-fourths 2/3 two-thirds
a (one) quarter three quarters 1/2 a (one) half 半年 half a year
一年半 one and a half years=one year and a half 2、分数的用法：“分数+of+限定词+名词复数”作主语时， 谓语用复数， “分数+of+限定词+不可数名词/名词单数” 作主语时谓语用单数。如： 1/3 One third of teachers are from America. 2/3 Two third of her money was spent on clothes. 3、百分数的表达方式：基数词+percent Forty percent of students in our class are boys.
Can you read a fraction?
1/2 1/3 1/4 24/25 3/4 3
three and six sevenths
one third /a third one quarter /a quarter/ one fourth
three fourths / three quarters
( B 1. ) of the students in this school is 2000,and of them are girls. A. The number; first fourth B. The number; one fourth C. A number; one second D. A number; three quarters (B) 2. is enough for me. A. One and a half hour B. One hour and a half C. One and half hour
B 3. Dick, it is the ________ time in ________ days that you’ve made the same mistake. A. two, three B. second, three C. two, third D. second, third (2007乌 鲁木齐) 4. It is said that the gravity(引力) on Mars is only about __________ of the A gravity on earth. A. three－eighths B. third－eighth C. three－eights D. third－eight