考点一：基数词
1. 基数词可以表示编号、钟点、年龄、年份等。“in one's +整十基数词的复数形式”表示“某人……多岁”。
2. 当基数词hundred, thousand, million, billion 等词前有具体数词修饰时，用单数形式；但当它们表示不确切的数量时，用复数形式，并且与of连用。
考点二：序数词
1. 序数词前一般要加定冠词the。序数词前有时用不定冠词a(n)，表示“又一；再一”。
2. 序数词前有名词所有格、形容词性物主代词等限定时，通常不用冠词。
考点三：分数
1. 分数由基数词和序数词构成。分子用基数词表示，分母用序数词表示。分子大于1时，分母要用序数词的复数形式。
2. 当分数用于复数可数名词或代词(指代复数可数名词)前作主语时，谓语动词用复数形式；当分数用于不可数名词或代词(指代不可数名词)前作主语时，谓语动词用单数形式。
【考例链接】
( )1. On her ______ birthday, she got an iPad as a gift from her father.
A. twelve B. twelfth
C. the twelve D. the twelfth
(2016四川泸州)
( )2. Tony's mom looks young and beautiful. It's hard to imagine she is already in her ______.
A. fifties B. fifty
C. fiftieths D. fiftieth
(2015 江苏苏州)
( )3. —Have you heard of TFBoys?
—Certainly. About ______ teenagers love them very much in our school.
A. hundreds B. two hundreds of
C. two hundreds D. two hundred
(2016辽宁丹东)
( )4. —If your parents wanted to have a ______ child, would you agree?
—Of course. But they should make it in ______ years’ time.
A. second; second B. two; two
C. second; two D. two; second
(2016湖北随州)
( )5. He has failed ______ times, but he won't give up a ______ chance.
A. third; four B. three; fourth C. third; fourth
(2016黑龙江齐齐哈尔)
( )6. ______ Kobe's fans watched his final match and ______ of them were men.
A. Million of; three fourths
B. Three millions; third four
C. Millions of; three fourths
D. Three million; third fours
(2016新疆乌鲁木齐)
( )7. Nowadays, ______ of the old people in the area ______ used to dancing on the square after supper.
A. two third; is B. two thirds; is C. two thirds; are
(2016湖北恩施)
（未完待续）
