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數學符號的英文表達
數學符號的英文表達
一、小數、分數、百分數
1. 小數表示法
小數點左邊的數通常按基數詞讀，若為三位以上的數，也可按編碼式讀法讀出，即將數字單個讀出；小數點右邊的數通常按編碼式讀法單個讀出。如：
6.86 six point eight six
14.15 fourteen point one five
345.456 three four five point four five six 或 three hundred and forty－five point four five six
小數中“0”的讀法：
“0”在小數中通常讀作nought(英)或zero(美)，也可讀作字母o。如：
0.08 (nought) point nought eight 或 (zero) point zero eight
9.07 nine point o seven
2. 百分數表示法
百分數中的百分號%讀作percent。如：
6% 讀作 six percent
0.6% 讀作 (nought) point six percent
500% 讀作 five hundred percent
3. 倍數表示法
倍數表示方法很多，如：
This room is four times as big as mine. 這個房間是我的房間的四倍。
This room is three times larger than mine. 這個房間比我的房間大二倍/是三倍。
The output of coal has doubled. 煤的產量增加了一倍。
My aunt is as old again as I am. 我姑姑年齡比我大一倍。
Productivity is increased three fold. 生產效率提高了兩倍。
The volume of the Sun is about 1,300,000 times that of the Earth. 太陽的體積約為地球的1300000倍。
4. 分數表示法
(1) 較小分數的一般讀寫方法。如：
1/3 one-third
2/3 two-thirds
3/5 three-fifths
(2) 較複雜分數的簡明讀寫方法。如：
22/9 twenty-two over nine
a/b a over b 或 a divided by b
43/97 forty-three over ninety-seven
(3) 整數與分數之間須用and連接。如：
four and a half nine and two fifths
(4) 分數用作前置定語時，分母要用單數形式。注意下列寫法與讀法。如：
a one-third mile 1/3英裏
a three-quarter majority 3/4的多數
二、加、減、乘、除表示法
1．加：用 and, plus, added to 等詞表示。
2＋4＝6 可譯為：
Two and four is six.
Two plus four is equal to six.
Two added to four equals six.
Two and four makes six.
Two plus four will be six.
If you add two to four, you get six.
2．減：用 minus, taken from, subtracted from 等表示。
8－3=5可譯為：
Eight minus three is five.
Eight minus three is equal to five.
Three taken from eight leaves five.
Three subtracted from eight leaves five.
Take three from eight and the remainder is five.
3．乘：用 multiply...by... / multiplied by / time 等表示。
3×5=15可譯為：
Multiply three by five is(gives) fifteen.
Three multiplied by five is fifteen.
Multiply three by five, you get fifteen.
Three times five is (makes, will be, equals, is equal to) fifteen.
4．除：用 divide...by... / divided by / divide...into... / into 等表示。
24÷8=3 可譯為：
Twenty-four divided by eight makes(is, equals) three.
Twenty-four divided by eight is equal to three.
Eight into twenty-four goes three times.
Divide eight into twenty-four, and you get three.
Divide twenty-four by eight, and you get three.
小結：
6+5＝11 Six plus five is eleven ./Six and five is eleven.
11-6＝5 Eleven minus six is five. /Six from eleven is five.
4×5＝20 Four multiplied by five is twenty./Four times five is twenty.
20÷4＝5 Twenty divided by four is five./Four into twenty goes five.
15:5＝3 The ratio of fifteen to five is three.
其他補充：
3的平方=9 Three squared/square is nine./The second power of 3 is 9./The square of 3 is 9./5 to the second power is 9.
2的立方=8 Two cubed is eight./......
16的-4次方=2 16 to the (power) minus 4 is 2./
2的4次方=16 The fourth power of two is sixteen./Two to the power 4 is sixteen.
X^(1/2)=Y The square root of X is Y.
X^(1/3)=Y The cubic root of X is Y.
X^(1/4)=Y The forth root of X is Y./X to the power of one over four.
a > b a is more/greater than b.
a>>b a is much greater than b.
a < b a is less than b.
a ≈ b a approximately equals to/is approximately equal to b.
a ≠ b a is not equal to b.
a ≡ b a is identically equal to b.
( ) round brackets/parentheses.
[ ] square brackets/angular brackets.
{ } braces.
|X| the absolute value of X.
(a-b-c×d)/e=f a plus b minus c multiplied by d, all divided by e equals f.
三、英語中倍數關係表達式
1）n times +形容詞（或副詞）比較級+than…
times是用來表示“乘”的（used to indicate multiplication）n times就是“乘以n”的意思。不論在任何句型中都包括基數100%在內。
[1] Asia is four times larger than Europe.
誤譯：亞洲比歐洲大4倍。
正譯：亞洲比歐洲大3倍。
評析：亞洲麵積4400萬平方公裏，歐洲麵積1016萬平方公裏。因此亞洲應該是歐洲麵積的四倍，即亞洲比歐洲大3倍。
[2] Sound travels nearly 3 times faster in copper than in lead.
聲音在銅中的傳播速度幾乎比在鉛中快2倍。
評析：聲音在銅中的傳播速度為2100m/s，在鉛中在的傳播速度為710m/s，可見聲音在銅中的傳播速度幾乎是鉛中的3倍，而不是比鉛快3倍。
[3] The volume of the earth is 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 +形容詞（或副詞）原級+as
[4] The oxygen atom is nearly 16 times as heavy as the hydrogen atom.
氧原子的重量幾乎是氫原子的16倍。
評析：經查，氧原子的重量為15.9994，氫原子量為1。
[5] The mercury atom is about 5 times as heavy as calcium atom.
汞的原子重量大約為鈣的5倍。
評析：經查，汞的原子量為200.59，鈣的原子量為40.08。
3) by + n times
[6] The steel output has increased by two times.
鋼產量已增加了一倍。
評析：即增加了（原數目-1）倍。
[7] The error probability of the equipment was reduced by 2.5 times through technical innovation.
通過技術革新，該設備的誤差概率降低了3/5。
評析：reduced by 2.5 times，漢語中不說“降低到二點五”，這時應換算成整數分母，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 television set was reduced by 3.4 times.
采用一種新工藝使這種電視的主要成本降低了71%。
評析：算成整數分母，即“降低到5/17” 或“降低了12/17”，但這樣仍不符合漢語習慣。在不要求絕對精確的情況下，可進一步換算成百分數，即“降低到29%”或“降低了71%”。
另外，由倍數換算成分數表示減少後的結果，譯成“減少到幾分之一”或“減少為幾分之一”。例如，
reduce by 3 times 減少到1/3 或減少了2/3
reduce by 5 times 減少到1/5 或減少了4/5
reduce by 10 times 減少到1/10 或減少了9/10
4)“倍數+upon/over”結構表示“增加到n倍，增加了或超過了（n-1）倍”
[9] The industrial output in our factory this year is ten times over that of 1999.
今年我們工廠的產量比1999年增加10倍。（×）
今年我們工廠的產量是1999年的10倍。
[10] He is five times upon your age.
他是你年齡的5倍。
[11] The total output value of the city’s light industry has grown over three times as against last year.
這個城市的輕工業總產值比去年增長了兩倍多。
[12] The number of the students in that school has been decreased more than 3 fold.
該校學生人數減少了2/3。（即減少到原來的1/3）
[13] The grain output in that county was two times over that of 1995.
那個縣的糧食產量比1995年增加了一倍。
5) 增減意義的動詞+倍數
應為“增加到原來的n倍”或 “增加了（n-1）倍”
[14] The cotton output in the county has increased four times.
該縣棉花產量增加了3倍。
[15] The sales of TV set have risen 3.5 fold.
電視機銷售量增加了2倍半。
[16] The weight of the bicycle has decreased 3 times.
這種自行車的重量減少了2/3。（即減少到1/3）
[17] The length of the rope has been shortened 5 fold.
繩子的長度縮短了4/5。（即縮短到1/5）
[18] If there were a bridge here, the distance would be shortened 4 times.
如果這裏有座橋，距離將縮短3/4。
6)“表示增減意義的詞+to+倍數”句型常譯為“增（降）至n倍”
[19] The number of the students has increased to three times.
學生人數增加到3倍。
[20] The price of rice has reduced to two thirds.
大米的價格減到原價的2/3。
① Exceed (increase, decrease, reduce)+by a factor of +倍數
增加到n倍，減少到1/n倍
[21] The speed exceeded the average speed by a factor of 2.5.
該速度超過平均速度的1.5倍。
[22] The price of farm tools has decreased by a factor of 4.
農具降到原價的1/4。
[23] This equipment will reduce the error probability by a factor of 5.
這種設備使誤差概率降低到原來的1/5。
② 表示“2倍”時，不能用two times，除了twice外，還可以用double， as …again as等
[24] He demanded double the usual fee.
他要了比平常多1倍的路費。
[25] A is as long again as B.
A的長度是B的2倍。
③ 表示“3倍”時，除可用three times外，還可用動詞treble或triple等表示。
[26] The grains in the area have trebled this year.
今年這個地區的糧食增加了2倍。
[27] Output should triple by next year.
到明年產量應增至三倍。
④ 在表示“4倍”或“4倍以上”時，除用“基數詞+times”外，還可用“基數詞+fold”的合成詞。
[28] We have produced four-fold as many electric fans as we did last year.
本年我們生產的電扇數量相當於去年的4倍。
[29] During that period its total output of industry increased (to) ten-fold.
在那個時期，工業總產值增加了9倍。
⑤ 在表示“不到1倍”時，還可用“分數+as …again as”表示。
[30] A is half as much again as B.
A比B多一半。
7) 倍數+the size (length, height) of …表示
[31] Shanghai is about 4 times the size of Changsha.
Shanghai is about 4 times as large as Changsha.
上海大約有長沙的4倍那麼大。
[32] In this workshop the output of July was 3.5 times that of January.
In this workshop the output of July was 3.5 times as much as that of January.
這個車間7月份的產量是1月份的3.5倍。
補充：
倍數增加
：
(一)
A is n times as great(long,much,…)as B.（1）
A is n times greater (longer,more,…)than B.（2）
A is n times the size (length,amount,…)of B.(3)
以上三句都應譯為；A的大小（長度,數量…）是B的n倍
[或A比B大（長，多，……）n-1倍].
Eg. This book is three times as long as （three times longer than，three times the length of）that one.
這本書的篇幅是那本書的3倍（即長兩倍）。
注：當相比的對象B很明顯時，than（as，of）B常被省去。
(二)
increase to n times（4）
increase n times/n-fold（5）
increase by n times（6）
increase by a factor of n（7）
以上四式均應譯為：增加到n倍（或：增加n-1倍）。
Eg. The production of integrated circuits has been increased to three times as compared with last year.
集成電路的產量比去年增加了兩倍。
Eg. The output of chemical fertilizer has been raised five times as against l986．
化肥產量比1986年增加了4倍。
Eg. That can increase metabolic rates by two or three times.
那可使代謝率提高到原來的2倍或3倍（即提高1倍或2倍）。
Eg. The drain voltage has been increased by a factor of four.
漏電壓增加了3借（即增加到原來的4倍）。
注：在這類句型中increase常被raise，grow，go/step up，multiply等詞所替代。
(三)
There is a n-fold increase/growth…（8）
應譯為：增加n-倍（或增至n倍）。
Eg. A record high increase in value of four times was reported.
據報道,價值破記錄地增長了3倍。
(四)
double (增加1倍)，treble（增加2倍），quadruple（增加3倍）。(9)
Eg. The efficiency of the machines has been more than trebled or quadrupled．
這些機器的效率已提高了2倍或3倍多。
(五)
此外，英語中還有一種用again而不用倍數詞來比較倍數的方法，如： A is as much (large，long，…)again as B.
A is twice as much (large，long，…)as B.（10）
應譯為：A比B多（大，長，……）1倍。
A is half as much (large， 1ong，…)again as B.
A is one and a half times as much (large， 1ong，…)as B.（11）
應譯為:A比B多（大，長……）一半（即A是B的一倍半）。
倍數減少
：
(一)
A is n times as small (light，slow，…)as B.（12）
A is n times smaller (lighter， slower，…)than B.（13）
以上兩句均應譯為：A的大小(重量，速度，……)是B的1/n
[或A比B小(輕，慢，……) (n-1)/n]。
Eg. The hydrogen atom is nearly l6 times as light as the oxygen atom.
氫原子的重量約為氧原子的1/16（即比氧原子約輕15/16）。
Eg. This sort of membrane is twice thinner than ordinary paper.
這種薄膜比普通紙張要薄一半（即是普通紙厚度的1/2）。
注：當相比的對象B很明顯時，than/as B常被省去。
(二)
decrease n times/n--fold（14）
decrease by n times（15）
decrease by a factor of n（16）
以上三式均譯為：減少到1/n[或：減少(n-1)/n]。 decrease常被reduce， shorten， go/slow down等詞替代。
Eg. Switching time of the new-type transistor is shortened 3 times. 新型晶體管的開關時間縮短了1/3（即縮短到2/3）。
Eg. When the voltage is stepped up by ten times，the strength of the current is stepped down by ten times.
電壓升高9倍，電流強度便降低9/10（即90％）。
Eg. The equipment reduced the error probability by a factor of 5.
該設備誤差概率降低了4/5。
(三)
There is a n-fold decrease/reduction…
應譯為：減至1/n [或：減少(n一1)/n]。（17）
Eg. A rapid decrease by a factor of 7 was observed．
發現迅速減少到1/7。
Eg. The principal advantage of the products is a two-fold reduction in weight.
這些產品的主要優點是重量減輕了1/2。
從上麵倍數增減句型及其譯法中不難看出：與漢語不同的是，英語在表述或比較倍數時，無論使用什麼句型(除了不含倍數詞的again句型外)都包括基礎倍數在內，因此都不是淨增或淨減n倍，而是淨增或淨減n-1倍。所以句型5、3表示的倍數增量=句型4；句型13表示的倍數比差＝句型12，且decrease(by)3 times應譯為“減少2/3”，而不是“減少3/4”。
最後更新：2017-04-03 05:39:27