數(shù)詞

　　定義：表示數(shù)目多少或順序多少的詞叫數(shù)詞，數(shù)詞分為基數(shù)詞和序數(shù)詞。表示數(shù)目多少的數(shù)詞叫基數(shù)詞;表示順序的數(shù)詞叫序數(shù)詞。

　　I基數(shù)詞

　　1.基數(shù)詞的構(gòu)成

　　(1)1-20

　　one,two,three,four,five,six,seven,eight,nine,ten,eleven,twelve,thirteen,fourteen,fifteen, sixteen, seventeen, eighteen, nineteen, twenty

　　(2)21-99 先說“幾十”，再說“幾”，中間加連字符。

　　23→twenty-three,34→thirty-four,45→forty—five,56→fifty-six,67→sixty-seven,78→seventy-eight,89→eighty-nine,91→ninety-one

　　(3)101—999先說“幾百”，再加and,再加末兩位數(shù)或末位數(shù);

　　586→five hundred and eighty-six,803→eight hundred and three

　　(4)l,000以上,先從右往左數(shù)，每三位數(shù)加一個(gè)“,”,第一個(gè)“,”前為thousand.第二個(gè)“,”前為

　　million,第三個(gè)“,”前為billion(美式)或thousand ,million(英式),然后一節(jié)一節(jié)地表示。

　　1,001→one thousand and one

　　9,785→nine thousand, seven hundred and eighty-five

　　18,423→eighteen thousand, four hundred and twenty-three

　　6,260,309→six million two hundred and sixty thousand three hundred and nine

　　750,000,000,000→seven hundred and fifty, billion(美式) seven hundred and fifty thousand million(英式)

　　2.基數(shù)詞的用法

　　(1)作主語

　　eg.Four Of them come from Paris.

　　(2)作賓語

　　eg.一 How many books would you like?

　　一I would like two.

　　(3)作表語

　　eg.Seven minus two is five.

　　(4)作定語

　　eg.There are three people in my family•

　　(5)作同位語

　　eg. You two will go swimming with us.

　　(6)表具體數(shù)字時(shí),hundred, thousand ,million用單數(shù)。

　　eg. There are six hundred students in our grade.

　　(7)表不確定的數(shù)字時(shí),數(shù)詞用復(fù)數(shù)。若帶名詞，再加of。 hundreds of(數(shù)百,成百上千的),thousands of(數(shù)干,成千上萬的),millions of(數(shù)百萬)two thousand (兩千)

　　Thousands and thousands of people have visited the city.成千上萬的人參觀了這座城市。

　　6x5=30 Five times six is thirty /six unutilized five is thirty.

　　8÷2=4 Eight divided by two is four.

　　VI倍數(shù)表示法

　　a. 主語+謂語+倍數(shù)(或分?jǐn)?shù))+ as + adj. + as

　　I have three times as many as you.　我有你三倍那么多。

　　b. 主語+謂語+倍數(shù)(分?jǐn)?shù))+ the size (amount，length…) of…

　　The earth is 49 times the size of the moon.　地球是月球的49倍。

　　c. 主語+謂語+倍數(shù)(分?jǐn)?shù))+ 形容詞(副詞)比較級+ than…

　　The grain output is 8 percent higher this year than that of last year.

　　今年比去年糧食產(chǎn)量增加8%。

　　d. 還可以用by+倍數(shù)，表示增加多少倍

　　The production of grain has been increased by four times this year.

　　今年糧食產(chǎn)量增加了4倍。

　　0.157 讀作：(zero)point one five seven