倍數(shù)表達(dá)法教案

1、答： 在寫作過程中或在口頭表達(dá)中， 有時(shí)要談到 “倍數(shù)” 問題， 現(xiàn)將其表達(dá)法作一歸納。1用形容詞表示甲是乙的幾倍時(shí)，用下面三個(gè)句型，用副詞表示則一般只用前兩個(gè)句 型。（ 1） , 倍數(shù)+形容詞（或副詞）的比較級(jí)+thanThis rope is twice longer than that one 這根繩的長(zhǎng)度是那根繩的三倍。（比那根繩長(zhǎng)二 倍）This hall is five times bigger than our classroom 這個(gè)大廳比我們的教室大五倍。（是我們教室的六倍）The car runs twice faster than that truck,這輛小車的速度比那

2、輛卡車快兩倍。（是那輛卡 車的三倍）（2）,倍數(shù)+as+形容詞（或 much）或副詞+asAsia is four times as large as Europe.亞洲的面積是歐洲的四倍。This big stone is three times as heavy as that one 這塊大石頭的重量是那一塊的三倍。 （這 塊石頭比那塊重二倍）The plane flew ten times as high as the kite,那架飛機(jī)飛行高度是那個(gè)風(fēng)箏的十倍。（高 出九倍）（ 3） , 倍數(shù) +the size（ length ， height, ） ofThis street i

3、s four times the length of that street 這條街是那條街的四倍長(zhǎng)。This hill is four times the height of that small one 這座山的高度是那座小山的四倍。（比 那座小山高三倍）也可用： The height of this hill is four times that of that small one 2要用名詞表示“量”的倍數(shù)時(shí)，則用以下兩個(gè)句型：（1）,倍數(shù) +more+名詞（可數(shù)，不可數(shù)） +thanThere are four times more books in our library than

4、 in yours 我們圖書館藏書（數(shù)量）是你 們圖書館藏書的四倍。（我們圖書館藏書比你們的多三倍。）We have produced twice more grain this year than we did last year 我們今年生產(chǎn)的糧食比 去年增長(zhǎng)一倍。（是去年的兩倍）（2）,，倍數(shù) +as many （或 much） + 名詞 + 其他+as,After the technique was introduced ， the factory produced twice as many tractors in 1988 as the year before 采用新的技術(shù)以后，

5、那個(gè)工廠 1988 年生產(chǎn)的拖拉機(jī)是前一年（1987 年）的兩倍。（比前一年增長(zhǎng)一倍）There is three times as much water in this pot as in that one. 這個(gè)壺里的水（量）是那個(gè)壺 里的三倍。倍數(shù)的表達(dá)法陜西 田世俊倍數(shù)表達(dá)法是高中英語(yǔ)教學(xué)的重點(diǎn)，也是歷屆高考的熱點(diǎn)。當(dāng)我們要表達(dá)甲是乙的幾倍時(shí)，通常用下面三個(gè)句型來表示：“A+吾數(shù)+形容詞或副詞的比較級(jí)+than+B”，表示“A比B大（長(zhǎng)、高、寬等）多少倍”。如：This rope is twice longer than that one.這根繩子是那根繩子的兩倍長(zhǎng)（比那根繩子長(zhǎng)一倍）

6、。This hall is five times bigger than our classroom.這個(gè)大廳比我們的教室大四倍 （ 是我們教室的五倍） 。The car runs twice faster than that truck.這輛小車的速度比那輛卡車快一倍（是那輛卡車的兩倍）?！癆銅數(shù)+as+形容詞或副詞的原級(jí)+as+B,表示“A正好是B的多少倍”。如：Asia is four times as large as Europe.亞洲的面積是歐洲的四倍。This big stone is three times as heavy as that one.這塊大石頭的重量是那塊的三倍

7、。The plane flew ten times as high as the kite. 那架飛機(jī)的飛行高度是那只風(fēng) 箏的十倍?！癆+音數(shù)+the size/height/length/width, etc+of+B ”，表示 “A 正好是 B 的多 少倍”。如：This street is four times the length of that one.這條街是那條街的四倍長(zhǎng)。This hill is four times the height of that small one.這座山的高度是那座小山的四倍。除掌握倍數(shù)表達(dá)的三個(gè)常規(guī)句型外，我們更要注意的是其常規(guī)句型的變形及其特殊規(guī)

8、律。一 . 常規(guī)句型的變形“times+more+ 名詞（可數(shù)或不可數(shù)）+than+被比對(duì)象”。如：There are five times more books in our library than in yours.我們圖書館里的書比你們圖書館多四倍。We have produced twice more grain this year than we did last year.我們今年生產(chǎn)的糧食是去年的兩倍?！皌imes as many/much+ 名詞+as+被比對(duì)象”。如：There is four times as much water in this pot as in th

9、at one.這個(gè)壺里裝的水是那個(gè)壺里的四倍。There are six times as many students as we expected. 學(xué)生數(shù)量是我們預(yù)期的 六倍?！?. times+over+ 被比對(duì)象”。如：The grain output in that village is twice over that of 2002.那個(gè)村的糧食產(chǎn)量是 2002 年的兩倍。“ . times+that+of+ 被比對(duì)象 ”。如：In this workshop, the output of July was 4.5 times that of January.這個(gè)車間 7 月份的產(chǎn)

10、量是1 月份的 4.5 倍?！?.times+compared with+ 被比對(duì)象”。如：The number of the students in our school has increased 4 times compared with 1980. 我們學(xué)校的學(xué)生人數(shù)比 1980 年增加了三倍?！?.times+what+ 從句”。如：The production is now three times what it was ten years ago.現(xiàn)在的產(chǎn)量比十年前增加了兩倍。二 . 倍數(shù) / 百分?jǐn)?shù)( percent ) +compared with/up on + 被比對(duì)象。

11、如：Our factory s output of TV sets in the first six months of this year was10% up compared with last year. 今年頭六個(gè)月我們廠電視機(jī)的產(chǎn)量與去年相比增加了10%。The industrial output of last year in our factory was 35%up on that of 2001.我們廠去年的工業(yè)產(chǎn)量比 2001 年增加了35%。三 . 用 double 表示倍數(shù)double 用作形容詞，表示“兩倍的”。如：The production is now doub

12、le what it was ten years ago.現(xiàn)在的產(chǎn)量是十年前的兩倍。double 用作動(dòng)詞，表示“是, 的兩倍。如：The output has been doubled in the past six years.在過去六年中產(chǎn)量已經(jīng)翻了一番。This brought a steady rise in the grain yield. In 2002 it nearly doubled that of 1980. 這使糧食產(chǎn)量不斷增長(zhǎng)，到 2002 年產(chǎn)量已經(jīng)比1980 年翻了一番。有這樣一道高考題：（ 2003 上海） The house rent is expensive

13、. Ive got about half the space I had at home andIm paying here.as three times muchas much three timesmuch as three timesthree times as much該題的正確答案為 D . 顯然本題是在考查倍數(shù)的表達(dá)法。 倍數(shù)表達(dá)法是高中英語(yǔ)教學(xué)的重點(diǎn)， 也是歷年的高考熱點(diǎn)之一。 掌握倍數(shù)的表達(dá)法對(duì)于同學(xué)們學(xué)好英語(yǔ)具有重要意義。 下 面對(duì)倍數(shù)的幾種表達(dá)法作一歸納：一、用 times 表示倍數(shù)（一般限于包括基數(shù)在內(nèi)三倍或三倍以上的數(shù)。表示兩倍的數(shù)， 一般用 twice ）。其句式有：

14、time升形容詞/副詞的比較級(jí)+than例如：Line AB is three times longer than line CD.線段 AB 是（線段） CD 的三倍長(zhǎng)。This hall is five times bigger than our classroom.這個(gè)大廳比我們的教室大5 倍。times +as播容詞/副詞的原級(jí)+as”例如：This table is three times as long as that one.這張桌子是那張桌子的三倍長(zhǎng)。This dictionary is five times as thick as the one you borrowed f

15、rom the library.這本詞典的厚度是你從圖書館借的那本（厚度）的 5 倍。”times + the 唱詞（如： size, height, weight, length, width 等）+ of例如：The earth is 49 times the size of the moon.地球的體積是月球的 49 倍。This river is three times the depth of that one.這條河是那條河的三倍深?！眛imes + more+名tBJ+ than 例如：He earns five times more money than he did ten

16、years ago.他現(xiàn)在掙的錢比十年前掙的多 5 倍。There are twice more students in our class than in theirs.我們班的學(xué)生人數(shù)比他們班多兩倍?！眛imes +as many （或 much ） + 名詞+ as 例如：Weve produced twice as much cotton this year as （ we did ） ten years ago.今年我們生產(chǎn)的棉花比十年前多了一倍。（漢語(yǔ)中的多一倍實(shí)際上也指兩倍一樣多。）He has got three times as many books as his siste

17、r.他擁有的書的數(shù)量是他妹妹的 3 倍?！眛imes + wha瞅句例如：The length of the road is four times what it was three years ago.這條路的長(zhǎng)度是三年前的 4 倍。The price of the meat is twice what it was last year.肉價(jià)是去年的兩倍?！眛imes + up on （或 over ） ”例如:The size of the sun is a million times over that of the earth.太陽(yáng)的體積比地球的體積大一百萬倍。He is three

18、times up on your age.他的年齡是你的 4 倍（或：比你的年齡大3 倍）?！?by + timeS 如：Compared with last year ， our coal output has increased by three times.與去年相比，我們的煤產(chǎn)量增長(zhǎng)了 3 倍。His speed is faster than mine by four times.他的速度比我的快4 倍?！眛imes + compared withi +被比較對(duì)象“例如：The number of the students in our school has increased for

19、 times compared with 1980.我們學(xué)校的學(xué)生人數(shù)比1980 年增加了 3 倍。times + that of +被比較對(duì)象”例如：In this workshop the output of July was 3.5 times that of January.這個(gè)車間七月份的產(chǎn)量是元月份的 3.5 倍。二、用分?jǐn)?shù)、百分?jǐn)?shù)表示倍數(shù)。例如：The box is one-third bigger than that one.這個(gè)盒子比那個(gè)盒子大三分之一。Last year the output value of industry was 59 percent higher t

20、han that of 1976.去年工業(yè)產(chǎn)值比 1976 年增長(zhǎng)了 59 。My command of English is not half so good as yours.我英語(yǔ)掌握得還不及你的一半兒好。again （一倍）， double （兩倍）， triple （三倍）， fourfold （四倍）等詞表示倍數(shù)。例如：My Aunt is as old again as I am.我姑姑的年齡比我大一倍。The top-brand clothes are often sold as double the normal price here.這里名牌衣服的售價(jià)經(jīng)常比正常的售價(jià)高一倍

21、。The new work procedure tripled the output.新工藝使產(chǎn)量增加兩倍。The output of grain increased fourfold.糧食產(chǎn)量增加了三倍。倍數(shù)表達(dá)法是歷屆高考的熱點(diǎn)。 當(dāng)我們要表達(dá)甲是乙的幾倍時(shí)， 通?？墒褂靡韵戮湫停罕稊?shù)+as+形容詞或副詞的原級(jí)+as+其它。這種結(jié)構(gòu)又常演變成下列兩類：倍 數(shù)+as+many可數(shù)名t復(fù)數(shù)+as;倍數(shù)+as+much杯可數(shù)名詞+as。如：There are seven times as many people as I expected. 是我預(yù)料的人數(shù)的七 倍。There is five t

22、imes as much coffee in this glass as in that one.這個(gè)杯子里的咖啡是那個(gè)杯子里的五倍。倍數(shù) +形容詞（或副詞）的比較級(jí)+ than+ 其它。如：The hall is five times bigger than our classroom.這個(gè)大廳的面積比我們教師大五倍。倍數(shù) +the size/height/length/width.etc.+of+ 其它。如：This road is six times the length of that one.這條路是那條路的六倍長(zhǎng)。計(jì)量名詞+of+名詞+be+l1數(shù)+that+of+其它。如：The

23、 size of the newly broadened square is four times that of the previous one. 新擴(kuò)建的廣場(chǎng)為以前的四倍大。倍數(shù) +what 從句。如：The production is now three times what it was ten years ago.現(xiàn)在的產(chǎn)量是十年前的三倍。倍數(shù)+more銘詞+than+其它。如：There are nine times more books in his bag than in yours.他書包里的書比你書包里的書多九倍。其它表達(dá)。如：她的年齡是我的兩倍。Shes twice/d

24、ouble my age.The average income of the staff has been increased by 50 percent compared with last year.與去年相比，該單位職工的收入已增加了50%。He runs faster than me by three times. 他跑得比我快三倍。 考查方向 1)倍數(shù)在句中的位置一般放在第一個(gè)as 前面或比較級(jí)前面或名詞前面。用 times 表示倍數(shù)時(shí)， 一般只限于表示包括基數(shù)在內(nèi)的三倍或三倍以上的數(shù)。表示兩倍可以用 twice 或 double, 一倍用 once.【重點(diǎn)歸納】除了我們初中所學(xué)的形

25、容詞的比較級(jí)的用法，本模塊我們主要?dú)w納幾種句式結(jié)構(gòu)：(一)含倍數(shù)的比較句型倍數(shù)+as+形容詞原級(jí)+as,。如：This bridge is three times as long as that one.His room is twice as big as mine;in other words,mine is only half as big as his.【特別提醒】“as,as ”中間加入名詞的句式：倍數(shù)+as+形容詞+a/an+可數(shù)名詞單數(shù)+as,倍數(shù)+as+形容詞+可數(shù)名t復(fù)數(shù)/不可數(shù)名詞+as,。如：Last year my brother twice as big a new

26、house as mine.He has collected more than three times as many stamps as I (have).I spent twice as much time on my studies as you did.【難點(diǎn)點(diǎn)撥】該結(jié)構(gòu)的省略：通常省略形容詞后面的名詞及比較的部分。如：I have to transfer( 轉(zhuǎn)乘) buses so I spend twice as much(money as others)for the bus every day.倍數(shù) +形容詞比較級(jí)+than, 。如：This street is four t

27、imes shorter than that one.Fear of danger is ten thousand times more terrifying than danger itself.【特別提醒】倍數(shù) +形容詞比較級(jí)+名詞 +than, 。如：He earns five times more money now than he did ten years ago.There are three times more books in our library than in yours.倍數(shù) +the+ 名詞 (如 size,height,weight,length,width,d

28、epth 等) +of, 。 如：This well is three times the depth of that one.另外，請(qǐng)注意下面兩種說法：( 1)倍數(shù) +what 從句。如：The length of the road is four times what it was three years ago.倍數(shù) +that of+ 被比較對(duì)象。如：Airmail charges almost twice or three times that of a normal mail.( 二)其它句式.比較級(jí)+and+比較級(jí)表示越來越,。如：Things are getting bette

29、r and better every day.Our country is becoming more and more beautiful.the+ 比較級(jí) , ， the+ 比較級(jí) , 表示“越 , ，就越 , ”。如：The more you have, the more you want.The more a man knows, the less he knows he knows.【知識(shí)擴(kuò)展】在形容詞比較級(jí)前可以加 a little,a bit,a lot,no,any,much,far,even,still等副詞（組），表示程度的加深。如：The result is much b

30、etter than we expected.Actually,health is far more important than wealth.一、1.A be倍數(shù)as計(jì)量形容詞原級(jí) as B.This tree is three times as tall as that one.這棵樹是那棵樹的三倍高。His father is twice as old as he.他父親的年紀(jì)有他兩倍大。.A be 倍數(shù) 計(jì)量形容詞比較級(jí) than B The Yangtze River is almost twice longer than the Pearl River.長(zhǎng)江差不多比珠江長(zhǎng)兩倍。T

31、he dictionary is exactly five times more expensive than that one.這本字典比那本恰好貴 5 倍。.A be 倍數(shù)the計(jì)量名詞 of B The newly broadened square id four times the size of the previous one.新擴(kuò)建的廣場(chǎng)是未擴(kuò)建時(shí)的四倍大。.The 計(jì)量名詞 of A be 倍數(shù) that of B The size of the newly broadened square is four times that of the previous one.新擴(kuò)建的

32、廣場(chǎng)為以前的四倍大。.其它Im twice/ double his age.我的年齡是他的兩倍。Ive paid five times the usual price for the stamp. 我出了 5 倍于往常的價(jià)格買這枚郵票。The average income of the staff has been increased by 50 percent compared with last year.與去年相比，該單位職工的收入增加了50%.The price of TVs are twofold（ adj. 兩部分的，雙重的）down over these years.近幾年來，電

33、視機(jī)的價(jià)格下降了兩倍。二、用times表示倍數(shù)（一般限于包括基數(shù)在內(nèi)三倍或三倍以上的數(shù)。表示兩倍的數(shù)，一般twice。）. times+形容詞（副詞）比較級(jí)+ than.This hall is five times bigger than our classroom.這個(gè)大廳比我們的教室大五倍。（是我們教室的六倍大）The car runs twice faster than that truck.這輛轎車的速度比那輛卡車快兩倍。（是那輛卡車的三倍快）.times +as+形容詞（或 much）或副詞原級(jí)十a(chǎn)s.The big box is four times as heavy as th

34、e small one.大箱子是小箱子的四倍重。Asia is four times as large as Europe.亞洲的面積是歐洲的四倍。Ten is twice as much as five.十是五的兩倍。The plane flew ten times as high as the kite.那架飛機(jī)飛行高度是那個(gè)風(fēng)箏的十倍。（高出九倍）.times +the +名詞（size, height, weight, length, width ） + ofYour playground is 900 metres wide, three times the size of ours

35、.你們操場(chǎng)有 900 米寬,是我們的三倍。This street is four times the length of that one.這條大街是那條街的四倍長(zhǎng)。This big tree is four times the height of that small one.這棵大樹的高度是那棵小樹的四倍。（比那棵小樹高三倍）也可譯成：The height of the big tree is four times that of that small one.4. times+more十名詞（可數(shù)，不可數(shù)）+than.There are four times more books in

36、our library than in yours.我們圖書館藏書 （數(shù)量） 是你們圖書館的四倍。（多三倍）We have produced twice more grain this year than we did last year.我們今年生產(chǎn)的糧食比去年增長(zhǎng)一倍。（是去年的兩倍）5. times + as many （或 much ）十名詞十其它 There is three times as much water in this pot as in that one.這個(gè)壺里的水 （量） 是那個(gè)壺里的三倍。There are five times as many students

37、as we expected.至 U 的人是我們預(yù)計(jì)的五倍。6. times +over +被比對(duì)象表示 增加倍。如：The grain output in that village was twice over that of 1978.那個(gè)村的糧食產(chǎn)量比一九七八年的增加了兩倍。7. times +thatof+被比對(duì)象 是倍。如：In this workshop, the output of July was 3. 5 times that of January.這個(gè)車間七月 份的產(chǎn)量是元月份的三點(diǎn)五倍。二、用.% （ percent, per cent ） + up on +被比對(duì)象Altogether, more than 70 percent of the surface of our planet is covered by water.我們地球的表面百分之七十以上被水覆蓋。Our factorys output of TV sets in 1998 was 400% up compared with 1980. 1998年我們工廠電視機(jī)的產(chǎn)量與1980