数词的用法

1）倍数表示法 a. 主语+谓语+倍数（或分数）+ as + adj. + as I have three times as many as you.　我有你三倍那么多。

b. 主语+谓语+倍数（分数）+ the size (amount，length…) of… The earth is 49 times the size of the moon.　地球是月球的49倍。

c. 主语+谓语+倍数（分数）+ 形容词（副词）比较级+ than… The grain output is 8 percent higher this year than that of last year. 今年比去年粮食产量增加8%。

d. 还可以用by+倍数，表示增加多少倍 The production of grain has been increased by four times this year. 今年粮食产量增加了4倍。

2）分数表示法 构成：基数词代表分子，序数词代表分母。分子大于1时，分子的序数词用单数，分母序数词用复数： 1/3 one-third ； 3/37 three and three-sevenths.