数词
什么是数词呢?
数词就是表示数量或顺序的词。分为基数词和序数词两类。
基数词
基数词就是表示数量的多少的词。如:There are 7 members in my family.在我家有7个人。数字7就是表示数量多少的基数词。
a.基数词的表达方法,如:
7 seven 18 eighteen 80 eighty
21 twenty-one 345 three hundred and forty-five
b.英语中的单位数词,如:
100 hundred 百 1000 thousand 千
1,000,000百万million
1,000,000,000 十亿billion
c, 表达一下基数词的读法
268 two hundred and sixty-eight
1369 one thousand three hundred and sixty-nine
2,684,651
two million six hundred eighty-four thousand six hundred and fifty-one
4,968,752,353
four billion nine hundred sixty-eight million seven hundred fifty-two thousand three hundred and fifty-three
序数词
序数词表示排列的顺序。如:The first time I saw him was yesterday.我昨天第一次见到他;第一次first就是一个序数词。
序数词的表达方法通常是在基数词的后面加th,如第四fourth,第xth,第七seventh。但第一、第二、第三的英语表达比较特殊,需要记忆。第五fifth是把基数词five结尾的ve变为f后再加th,而第九是去掉了基数词末尾的e后加th,变为ninth。具体的序数词的表达大家可以学习下表:
数词的其他用法:
1)小数表达法
小数点左边的数通常按基数词读,若为三位以上的数,也可按编码式读法读出,即将数字单个读出;小数点右边的数通常按编码式读法单个读出。
6.86 读作:six point eight six
14.15 读作:fourteen point one five
345.456 读作:three four five point four five six
也可以读作:three hundred and forty-five point four five six
0通常读作zero,也可读作字母o。如:
9.07 nine point o seven或nine point zero seven
2)倍数表达法
倍数通常是用基数词+times来表达,如:
Productivity has increased three times.
倍数的表达也可以用在比较级中,如:
The girl is ten times cleverer than her brother.
倍数的表达还可以用在as…as…的比较结构中,如:
Americans eat twice as much proteins as they actually need every day.
3)百分数的表达
百分数:其中的百分号%读作percent。如:
6% 读作:six percent
0.6% 读作:zero point six percent
500% 读作:five hundred percent
12.34% 读作:twelve point three four percent
4)分数表示法
a. 真分数。分子是按基数词来读,而分母是按序数词来读,如果分子>1,则分母的序数词要加s。如:
1/3 读作:one-third
2/3 读作:two-thirds
3/5 读作:three-fifths
b.假分数。如:
22/9 读作:twenty-two over nine
97/43 读作:ninety-seven over forty-three
c.带分数。整数与分数之间须用and连接。如:
四又二分之一 读作:four and a half
九又五分之二 读作:nine and two fifths
5)加减乘除运算
6+5=11 读作:Six plus five is eleven.
或:Six and five is eleven.
11-6=5 读作:Eleven minus six is five.
或Six from eleven is five.
4×5=20 读作:Four times five is twenty
或:Four multiplied by five is twenty.
20÷4=5 读作:Twenty divided by four is five.
或:Four into twenty goes five.
15:5=3 读作:The ratio of fifteen to five is three.
2的2次方是4 读作:Two squared is four.
2的3次方是8 读作:Two cubed is eight.
2的4次方是16读作:The fourth power of two is sixteen.
a > b 读作:a is more than b.
a < b 读作:a is less than b.
a ≈ b 读作:a approximately equals to b.
a ≠ b 读作:a is not equal to b
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