分数的分子用基数词表示，分母用序数词表示，若分子大于1，分母需用复数。

　　two-thirds(2/3)，one-third(1/3)， nine-tenths (9/10)， five-twelfths(5/12)。

　　特殊表达法有：one half (1/2)，a quarter (1/4)， three quarters (3/4) .

　　考试重点

　　基数词可以和其他词一起构成合成形容词，在句子中作定语，名词不能加s.

　　数词部分需特别注意dozen， hundred， million， billion 等词。表示具体数字时，这些词用单数形式，表示不具体的数字时，须用dozens of， hundreds of 这类的结构。

　　I want three dozen of these.

　　He has been there dozens of times.

　　当数词与名词及其他词构成合成形容词时，合成形容词中间若用连字符，则其中的名词须用单数形式。

　　The homework for the next period is to write a two-hundred-word composition about your hometown.

　　Mary is a eleven-year-old girl.

　　(Mary is eleven years old.)

　　典型例题

　　1. In ______ century computers will be used more widely.

　　A. twenty-one B. the twenty-one C. twenty-first D. the twenty-first

　　序数词前加the.

　　答案 D

　　5. “What did the professor tell you to do?”

　　“I had to write a ______ report. ”

　　A. two thousand words B. two-thousands-word

　　C. two-thousand-word D. two-thousand words

　　答案 C

　　6. “Did you buy anything at the clothing sale?”

　　“Yes， I bought three _____ ties for just twelve dollars.”

　　A. five dollars B. five-dollars C. five-dollar D. fifth dollar

　　答案 C

　　8. What date is it ? It's ________.

　　A. July twentieth-first B. July the twenty-first

　　C. the twenty-first of July D. Both B and C

　　7月21日：July the twenty-first

　　the twenty-first of July

　　答案：D

　　10. “Rex told me you have moved.”

　　“Yes， into a _______.”

　　A. two-storey house B. house of two story

　　C. house of two stories D. two-stories house

　　答案：A