深圳牛津英語(yǔ)七年級(jí)Chapter4PPT課件

1、A What do you know about?1 a decimal numbers2 a pair of odd numbers 3 a fraction4 zero5 add;plus6 subtract;minus7 mutiply; times 8 divide9 a number showing degrees10 a percentage11 a pair of even numbers12 equalsA +B 0C 5/8D E =F 13 45G 8 210H 90I J 0.82 K 45%L 第1頁(yè)/共67頁(yè)第2頁(yè)/共67頁(yè)第3頁(yè)/共67頁(yè)Calculating Ma

2、chine第4頁(yè)/共67頁(yè)Calculating Machine one of the first calculating machines accurate and fast representbeadswires 第5頁(yè)/共67頁(yè)Calculating Machineaddsubtractmultiply divide percentagesquare root第6頁(yè)/共67頁(yè)Calculating Machineaddsubtractmultiplydividepercentagessquare roots第7頁(yè)/共67頁(yè)Calculating Machine第8頁(yè)/共67頁(yè)Calcul

3、ating Machine powerful a flash in your whole lifetimea computer第9頁(yè)/共67頁(yè)Calculating MachineA _ is a very _ calculating machine. In _, it can do a calculation that you could not do _.a computer第10頁(yè)/共67頁(yè)第11頁(yè)/共67頁(yè)第12頁(yè)/共67頁(yè)第13頁(yè)/共67頁(yè)Why do people still use abacuses today?第14頁(yè)/共67頁(yè)What can an electronic ca

4、lculator do?第15頁(yè)/共67頁(yè)How fast can Shakuntala Devi calculate?第16頁(yè)/共67頁(yè)How long can a computer do a calculation?第17頁(yè)/共67頁(yè)How long did the computer take to solve the difficult problem?第18頁(yè)/共67頁(yè)What should people do to make computers calculate? program them with instructions第19頁(yè)/共67頁(yè)What do the beads on

5、 the wires represent? ones, tens, hundreds, thousands and so on.第20頁(yè)/共67頁(yè)How many languages do you know? Everyone knows at least two his or her own language and the international language of numbers.Numbers: everyones language（他或她自己的語(yǔ)言）第21頁(yè)/共67頁(yè) Ancient numbers In ancient times, people wrote numbers

6、 in many different ways. However, they nearly all counted in tens.different ways of writing the number 6（在古代）（以很多不同的方式）（以十為單位）第22頁(yè)/共67頁(yè) Zero The system of numbers today consists of the numbers from 1 to 9 and 0(zero). The Indians first invented and developed the 1 to 9 system of numbers. They then i

7、nvented the zero. The invention of the zero helped people write big numbers and calculate more easily. Now use each of these ten numbers once to write the biggest number. What is it?（數(shù)字體系）（invent. v. invention n. inventor n.）第23頁(yè)/共67頁(yè)1 ancient: many many years ago (a)2 consists of: includes (b) 3 in

8、vented: made for the first time (b)4 accurate: without mistakes (a)5 percentages: amounts out of a hundred (a) C1 Find these words in the article on page 45. Read the words around them and choose the best meanings.第24頁(yè)/共67頁(yè) A B 1 international a grew bigger or stronger 2 system b a group of things w

9、orking together 3 developed c count with numbers 4 calculate d strong 5 bottom e used by more than one country or nation 6 powerful f in the lowest place C2 Find the words in Column A in the article and match them with the meanings in Column B.第25頁(yè)/共67頁(yè) 1 A calculating machine using wires and heads.

10、 An _ 2 A small machine using electronic power to do calculations. A _ 3 A very powerful machine for doing calculations. A_C3 What do the following descriptions refer to? Write down the correct names in the blanks. calculatorcomputerabacus第26頁(yè)/共67頁(yè) May asks T M Li, the writer, some questions about h

11、is article on numbers. His answers are not always clear. Read the article and make Lis answers clearer. Write one word in each blank. 1 Every one knows it. Knows what? The Language of numbers.第27頁(yè)/共67頁(yè) 2 Long ago, people wrote them in many different ways. Wrote what? Numbers.3. People all count in t

12、his way. In what way? In tens.4. The Indians invented that system of numbers. Which system of numbers? The 1 to 9 system.第28頁(yè)/共67頁(yè) 5 The invention helped people write in big numbers. What invention? The invention of the zero. 6 They are fast and accurate. What? Abacuses. 7 Computers are very powerfu

13、l ones. Very powerful what? Calculating machines.第29頁(yè)/共67頁(yè)Language points第30頁(yè)/共67頁(yè)1. at least 至少= not less than We should recite at least 10 English words every day.反義詞: at most 至多The concert hall can hold at most 1,000 people.第31頁(yè)/共67頁(yè)2. in ancient times 在古代= long long ago= once upon a timeIn ancie

14、nt times, people used stones as money.ancient 反義詞: modern 現(xiàn)代的times = age n. 時(shí)代 第32頁(yè)/共67頁(yè)3. consist of 由組成= include = be made up of Our class consists of 25 girls and 30 boys.4. invent = make sth. for the first time v. 發(fā)明; 創(chuàng)造The ancient Chinese invented the compass.invention n. 發(fā)明 inventor 發(fā)明家第33頁(yè)/共6

15、7頁(yè)5.develop = grow better or bigger v. 發(fā)展; 發(fā)育 development n. 發(fā)展The Indians first invented and developed the 1 to 9 system of numbers.developing adj. 發(fā)展中的developed adj. 發(fā)達(dá)的India is a developing country. The USA is a developed country.第34頁(yè)/共67頁(yè)6. help sb (to ) do sth. = help sb. with sth.I like helpin

16、g my mother do the housework.= I like helping my mother with the housework.7. stand for = represent 代表; 表示PRC stands for Peoples Republic of China. 第35頁(yè)/共67頁(yè)8. in a flash = very quickly = in a very short time 一瞬間;很快A computer can do a calculation in a flash.電腦可以在一瞬間完成計(jì)算.9. Why not do sth.? = Why don

17、t you do sth.?第36頁(yè)/共67頁(yè)Why not see a film tonight? = Why dont you see a film tonight?10.buy sb.sth.= buy sth. for sb.My mother bought me a new bike last month.=My mother bought a new bike for me last month.第37頁(yè)/共67頁(yè)第38頁(yè)/共67頁(yè)I .Imperative sentences 祈使句 1 祈使句祈使句:表示請(qǐng)求表示請(qǐng)求,命令命令,勸告勸告,祝愿或建議的句子祝愿或建議的句子. e.

18、g. Close the window, please. e.g. Be quiet.2 使用祈使句應(yīng)注意的幾點(diǎn)使用祈使句應(yīng)注意的幾點(diǎn).A: 肯定祈使句的謂語(yǔ)總是用動(dòng)詞原形肯定祈使句的謂語(yǔ)總是用動(dòng)詞原形. Be careful.小心小心 Have a good time.愿你玩得開(kāi)心愿你玩得開(kāi)心.第39頁(yè)/共67頁(yè)B: 否定祈使句. 祈使句否定式的構(gòu)成方法是在動(dòng)詞原形前加dontDont laugh.不要笑.Dont be late again.不要再遲到了.C:與please連用.可用于句首或句末.Sit down, please. 請(qǐng)坐.Please dont get angry. 請(qǐng)不要

19、生氣.第40頁(yè)/共67頁(yè)D:以let開(kāi)頭的祈使句.Let me help you. 讓我?guī)椭?Lets go to the cinema. 我們一起去電影院. 這類(lèi)祈使句的否定式的形式如下:Lets not hurry.let后的動(dòng)詞要用原形.第41頁(yè)/共67頁(yè)II. 加減乘除表示法加減乘除表示法1. “加”用plus，and或add表示； “等于”用is, equal等詞表示。2+3=? 可表示為： How much is two plus three?2+3=5 Two plus three is five Two and three is equal to five Two and t

20、hree is five Two added to three is five 第42頁(yè)/共67頁(yè)加減乘除表示法加減乘除表示法2. “減”用 minus或 subtract表示106? How much is ten minus six?10-6=4 Ten minus six is four Subtract six from ten ,and we get four. 第43頁(yè)/共67頁(yè)3.“乘”用times或multiply表示3X4? How much is three times four?3X4=12 Three times four is twelveMultiply three

21、 by four，we get twelve Three multiplied by four is twelve 第44頁(yè)/共67頁(yè)4. “除”用divide的過(guò)去分詞形式表示164=? How much is sixteen divided by four?1644 Sixteen divided by four is four Divide sixteen by four , and we get four. 第45頁(yè)/共67頁(yè) 有關(guān)數(shù)字的命令和陳述 數(shù)字命令 Add 甲 and (to) 乙 甲+乙 Subtract 甲 from 乙 乙 - 甲 Multiply 甲 by 乙 甲乙

22、Divide 甲 by 乙 甲乙Add 3 and (to) 9Subtract 3 from 9 Multiply 3 by 9 Divide 9 by 3 3+9 9-3 39 93 第46頁(yè)/共67頁(yè) 數(shù)字的陳述 甲Plus乙is /equals 丙 甲+乙= 丙 甲minus乙is /equals丙甲-乙=丙 甲 times乙 is /equals丙 甲乙=丙 甲 divided by乙 is /equals 丙 甲乙=丙 3 plus 9 is /equals 12 3 +9 =12 9 minus 3 is /equals 3 9 - 3 = 6 3 times 9 is /equ

23、als 27 3 9 =27 9 divided by 3 is /equals 12 9 3 = 6第47頁(yè)/共67頁(yè) 練習(xí)數(shù)字命令法 A _ 2 _ 10 S _ 4 _ 5 M _ 3 _ 7 D _ 6 _ 2用數(shù)字陳述法轉(zhuǎn)換數(shù)字命令法 _ p_ _ is /equals 12 _ m _ _ is /equals 1 _ t_ _ is /equals 21 _ d _ by _ is /equals 3ddandubtractfromultiplybyivideby2lus105inus43imes76ivided2第48頁(yè)/共67頁(yè) III. 基數(shù)詞和序數(shù)詞基數(shù)詞:表示人或事物的

24、數(shù)量 Eg. One ,Two 13-19都是以 teen結(jié)尾 表幾十幾時(shí)，在十位數(shù)和個(gè)位數(shù)之間添加連字符“-” E.g. twenty-one 21 表幾百時(shí)，百位數(shù)與十位數(shù)或者百位數(shù)與個(gè)位數(shù)之間加and. three hundred and twenty 320 One hundred and one 101 第49頁(yè)/共67頁(yè)基數(shù)詞表示確切整數(shù)時(shí)，hundred /thousand后不加s E.g. 200 two hundred 當(dāng)基數(shù)詞表示不確定數(shù)字，如 數(shù)十個(gè)的成百的，成千上萬(wàn)基數(shù)詞以復(fù)數(shù)形式出現(xiàn)如： tens of 數(shù)十個(gè)的 hundreds of 數(shù)百個(gè)的 數(shù)千個(gè)的數(shù)千個(gè)的數(shù)百

25、萬(wàn)個(gè)的數(shù)百萬(wàn)個(gè)的Thousands ofMillions of 第50頁(yè)/共67頁(yè)序數(shù)詞：表示人或事物的順序序數(shù)詞：表示人或事物的順序 first/second/third 序數(shù)詞變化規(guī)律序數(shù)詞變化規(guī)律 序數(shù)詞是在基數(shù)詞的基礎(chǔ)上變化而成的序數(shù)詞是在基數(shù)詞的基礎(chǔ)上變化而成的多數(shù)序數(shù)詞在基數(shù)詞的基礎(chǔ)上加多數(shù)序數(shù)詞在基數(shù)詞的基礎(chǔ)上加 t h four fourth seven seventh第第1,第第2,第第3要注意要注意one first two second three third 8要減要減t , 9要減要減e再加再加thE.g. eight eighth nine ninth基數(shù)詞以基數(shù)詞

26、以 ve結(jié)尾，變結(jié)尾，變 ve 為為f再加再加 th thirty thirtieth five fifth第51頁(yè)/共67頁(yè)IV.小數(shù)表示法讀法小數(shù)點(diǎn)的左邊按基數(shù)詞讀（當(dāng)小數(shù)點(diǎn)左邊為零時(shí)，零可省略不讀），小數(shù)點(diǎn)讀point，小數(shù)點(diǎn)右側(cè)各數(shù)位單獨(dú)朗讀0.5 zero point five ( point five)72.78 1.345 seventy-two point seven eightone point three four five 當(dāng)小數(shù)數(shù)值大于1時(shí) ，小數(shù)后的名詞用復(fù)數(shù)；當(dāng)小數(shù)數(shù)字小于1時(shí)，小數(shù)后面的名詞用單數(shù) 1.5噸 one point five tons 0.49噸 ze

27、ro point four nine ton 第52頁(yè)/共67頁(yè)第53頁(yè)/共67頁(yè)Now try a quiz about numbers. Listen to the instructions on the recording, and circle the right answer.1 1 80 80 49 49 17172 2 2.66 2.66 26% 26% 2/62/63 3 $75 $75 75% 75% 7575o o4 4 1/8 1/8 0.75 0.75 33335 5 56 56 65 65 66666 6 9090o o 90% 90% 1/9 1/97 2565 3

28、881 7 2565 3881 2566 28812566 2881 2565 2881 2565 28818 1.8% 8 1.8% 80%80% 18% 18%9 $ 5,000 9 $ 5,000 $ 50, 000$ 50, 000 $ 50,000,000 $ 50,000,00010 30.510 30.5o o 13.513.5o o 35 35o o 第54頁(yè)/共67頁(yè)1 Which one of these is an even number?2 Which one of these is a fraction?3 Which one of these is a percen

29、tage?4 Which one of these is a decimal number?5 Which one of these is an odd number?第55頁(yè)/共67頁(yè)6 Which one of these is a number showing degrees?7 My phone number is 2565 2881.8 18 per cent of my classmates come to school on foot.9 This ring costs fifty thousand dollars.10 The highest temperature today was 30 point 5 degrees.第56頁(yè)/共67頁(yè)第57頁(yè)/共67頁(yè)第58頁(yè)/共67頁(yè)第59頁(yè)/共67頁(yè)第60頁(yè)/共67頁(yè)第6