问英语中倍数怎么表达

1）n times+形容词（或副词）比较级+than…
times是用来表示“乘”的（used to indicate multiplication）n times就是“乘以n”的意思。不论在任何句型中都包括基数100%在内。[1]asia ** four times larger than europe.
误译：亚洲比欧洲大4倍。正译：亚洲比欧洲大3倍。评析：亚洲面积4400万平方公里，欧洲面积1016万平方公里。因此亚洲应该是欧洲面积的四倍，即亚洲比欧洲大3倍。[2]sound tr**els nearly 3 times faster in copper than in lead.
声音在铜中的传播速度几乎比在铅中快2倍。评析：声音在铜中的传播速度为2100m/s，在铅中在的传播速度为710m/s，可见声音在铜中的传播速度几乎是铅中的3倍，而不是比铅快3倍。[3]the volume of the earth ** 49 times larger than that of the moon.
地球的大小是月球的49倍。或：地球比月球大48倍。2)n times+形容词（或副词）原级+as
[4]the oxygen ** ** nearly 16 times as he**y as the hydrogen **.
氧原子的重量几乎是氢原子的16倍。评析：经查，氧原子的重量为15.9994，氢原子量为1。[5]the mercury ** ** about 5 times as he**y as calcium **.
汞的原子重量大约为钙的5倍。评析：经查，汞的原子量为200.59，钙的原子量为40.08。3)by+n times
[6]the steel output has increased by two times.
钢产量已增加了一倍。评析：即增加了（原数目-1）倍。[7]the error probability of the equipment was reduced by 2.5 times through technical innovation.
通过技术革新，该设备的误差概率降低了3/5。评析：reduced by 2.5 times，汉语中不说“降低到二点五”，这时应换算成整数分母，即降低到“五分之二”，或降低了“五分之三”。[8]by using a new process the prime cost of the telev**ion set was reduced by 3.4 times.
采用一种新工艺使这种电视的主要成本降低了71%。评析：算成整数分母，即“降低到5/17”或“降低了12/17”，但这样仍不符合汉语习惯。在不要求绝对精确的情况下，可进一步换算成百分数，即“降低到29%”或“降低了71%”。另外，由倍数换算成分数表示减少后的结果，译成“减少到几分之一”或“减少为几分之一”。例如，
reduce by 3 times 减少到1/3 或减少了2/3
reduce by 5 times 减少到1/5 或减少了4/5
reduce by 10 times 减少到1/10 或减少了9/10
4)“倍数+upon/over”结构表示“增加到n倍，增加了或超过了（n-1）倍”
[9]the industrial output in our factory th** year ** ten times over that of 1999.
今年我们工厂的产量比1999年增加10倍。（×）
今年我们工厂的产量是1999年的10倍。[10]he ** five times upon your age.
他是你年龄的5倍。[11]the total output value of the city’s light industry has grown over three times as against last year.
这个城市的轻工业总产值比去年增长了两倍多。[12]the number of the students in that school has been decreased than 3 fold.
该校学生人数减少了2/3。（即减少到原来的1/3）
[13]the grain output in that county was two times over that of 1995.
那个县的粮食产量比1995年增加了一倍。5)增减意义的动词+倍数
应为“增加到原来的n倍”或“增加了（n-1）倍”
[14]the cotton output in the county has increased four times.
该县棉花产量增加了3倍。[15]the sales of tv set h**e r**en 3.5 fold.
电视机销售量增加了2倍半。[16]the weight of the bicycle has decreased 3 times.
这种自行车的重量减少了2/3。（即减少到1/3）
[17]the length of the rope has been shortened 5 fold.
绳子的长度缩短了4/5。（即缩短到1/5）
[18]if there were a bridge here,the d**tance would be shortened 4 times.
如果这里有座桥，距离将缩短3/4。6)“表示增减意义的词+to+倍数”句型常译为“增（降）至n倍”
[19]the number of the students has increased to three times.
学生人数增加到3倍。[20]the price of rice has reduced to two thirds.
大米的价格减到原价的2/3。① exceed(increase,decrease,reduce)+by a factor of+倍数
增加到n倍，减少到1/n倍
[21]the speed exceeded the **erage speed by a factor of 2.5.
该速度超过平均速度的1.5倍。[22]the price of farm tools has decreased by a factor of 4.
农具降到原价的1/4。[23]th** equipment will reduce the error probability by a factor of 5.
这种设备使误差概率降低到原来的1/5。② 表示“2倍”时，不能用two times，除了twice外，还可以用double，as…again as等
[24]he demanded double the usual fee.
他要了比平常多1倍的路费。[25]a ** as long again as b.
a的长度是b的2倍。③ 表示“3倍”时，除可用three times外，还可用动词treble或triple等表示。[26]the grains in the area h**e trebled th** year.
今年这个地区的粮食增加了2倍。[27]output should triple by next year.
到明年产量应增至三倍。④ 在表示“4倍”或“4倍以上”时，除用“基数词+times”外，还可用“基数词+fold”的合成词。[28]we h**e produced four-fold as many electric fans as we did last year.
本年我们生产的电扇数量相当于去年的4倍。[29]during that period its total output of industry increased(to)ten-fold.
在那个时期，工业总产值增加了9倍。⑤ 在表示“不到1倍”时，还可用“分数+as…again as”表示。[30]a ** half as much again as b.
a比b多一半。7)倍数+the size(length,height)of…表示
[31]shanghai ** about 4 times the size of changsha.
shanghai ** about 4 times as large as changsha.
上海大约有长沙的4倍那么大。[32]in th** workshop the output of july was 3.5 times that of january.
in th** workshop the output of july was 3.5 times as much as that of january.
这个车间7月份的产量是1月份的3.5倍。