七年级英语上册 CHAPTER FOUR The world of numbers课件 深圳牛津版

1、A What do you know about We all use numbers in our daily life. Numbers are an international language. What do you know about the language of numbers? Learn the following: A decimal number is written as A decimal number is written as a dota dot. .eg. 0.65 (zero point six five/ sixty-five)eg. 0.65 (ze

2、ro point six five/ sixty-five) 8.08 (eight point o eight.) 8.08 (eight point o eight.)Read the following:Read the following:7.53, 3.42, 0.01, 86.207.53, 3.42, 0.01, 86.201 a decimal number( 小数）小数） Odd numbers cannot be divided by two Odd numbers cannot be divided by two to give a whole number withou

3、t a to give a whole number without a fraction.fraction. 2 odd numbers (奇数）奇数） 3 even numbers (奇数）奇数） Even numbers can be divided by two to Even numbers can be divided by two to give a whole number.give a whole number. A fraction is the exact division of a A fraction is the exact division of a number

4、.number. eg. : one half eg. : one half 2/3: two thirds 2/3: two thirds a quarter a quarter 1/10 one tenth 1/10 one tenthRead the following:Read the following:3/5, 6/11, 1/83/5, 6/11, 1/8 4 a fraction (分数分数） 5 plus , add (加）加） Two plus five is seven.Two plus five is seven.Two and five is seven.Two an

5、d five is seven.Two added to five is seven.Two added to five is seven.3+ 12 =?3+ 12 =?What is 3 plus twelve? What is 3 plus twelve? Read the following:Read the following:25 + 24 = 49 30 + 12 = ?25 + 24 = 49 30 + 12 = ? 6 minus (减，减号，负号）减，减号，负号） subtract (减减)12-3=912-3=9Twelve minus three is nine.Twe

6、lve minus three is nine.Three subtracted from twelve is nine.Three subtracted from twelve is nine. Read the following:Read the following:2-2=0 19- 12=7 97-65=?2-2=0 19- 12=7 97-65=? 7 times, multiply 乘乘 Two times three is six.Two times three is six.Two and three multiply makes six.Two and three mult

7、iply makes six.Two multiplied by three makes 6.Two multiplied by three makes 6. Read the following:Read the following:16 16 4 = 64 5 4 = 64 5 3 = 15 3 = 15 8 divide 除除3030 6 = 5 6 = 5Thirty divided by six is five.Thirty divided by six is five.Read the following:Read the following:20 20 4 = 5 18 4 =

8、5 18 3 = 6 3 = 6 45% 45% = = 90 90o oa percentageequalsa number showing degreesMatch the words with the pictures, signs and numbers.1 a demical number2 a pair of odd numbers3 a fraction4 zero5 add; plus6 subtract; minus 7 multiply, times8 divide9 a number showing degrees10 a percentage11 a pair of n

9、umbers12 equalsA What do you know aboutjfcbalidhkge1 abacus: an old form of calculator2 accurate: with no mistakes3 ancient: very old4 at least : not less than5 bead: a small ball with a hole through the middle6 calculate: use numbers to find answers7 consist of: be made up of something8 develop: gr

10、ow bigger and/ or better9 electronic: using electrons for power 10 electronic: using electrons for power11 figure: a symbol rather than a word12 flash: a very short time, an instant13 however: yet14 international: connected to more than one country or nation15 invent: make for the first time16 nearl

11、y: almost17 powerful: strong18 system: group of things/ parts that work togetherFill in the blanks with correct words. If you _ 8 and 5 , you get 13. If you _ 8 and 5 , you get 13. I use the pocket _ to check my I use the pocket _ to check my answers.answers. The UN is an _ organization The UN is an

12、 _ organization which helps to keep a peaceful world.which helps to keep a peaceful world. The underground is part of Shenzhens The underground is part of Shenzhens transport _.transport _. The _ Chinese drew pictures to The _ Chinese drew pictures to show different meanings.show different meanings.

13、addcalculatorinternationalsystemancientFill in the blanks with correct words.6. Before calculators were invented, the 6. Before calculators were invented, the Chinese people used _ to count.Chinese people used _ to count.7. Weather reports are not always _.7. Weather reports are not always _. Edison

14、 _the light bulb after he had Edison _the light bulb after he had failed many times.failed many times. If you _8 from 16, you get 8.If you _8 from 16, you get 8. Our country is more _than before. Our country is more _than before. If you _ 28 by 7, the answer is 4.If you _ 28 by 7, the answer is 4.8.

15、8. The committee _of ten members. The committee _of ten members.abacusaccurateinventedsubtractpowerfuldivideconsistsC1 Find these words in the article on page 73. Read the words around them and choose the best meanings. 1 ancient: many many years ago2 consists of: includes3 invented: made for the fi

16、rst time4 accurate: without mistakes5 percentages: amounts out of a hundred C2 Find the words in Column A in the diary on page C2 Find the words in Column A in the diary on page 62 and match them with the meanings in Column 62 and match them with the meanings in Column B.B. A 1 international 2 syste

17、m3 developed4 calculate5 bottom6 powerful Ba grew bigger or strongerb a group of things working togetherc count with numbersd stronge used by more than one country or nationf in the lowest placeC3 What do the following descriptions refer to? Write down the correct names in the blanks.1 A calculating

18、 machine that uses wires and 1 A calculating machine that uses wires and heads.heads. An _An _2 A small machine that does calculations.2 A small machine that does calculations. A _A _3 A very powerful machine for doing 3 A very powerful machine for doing calculations.calculations. A_A_ abacuscalcula

19、torcomputerCalculating MachineCalculating Machinenone of the first calculating machines naccurate and fastnrepresentbeadswires Calculating Machineaddsubtractmultiply divide percentagesquare rootCalculating Machineaddsubtractmultiplydividepercentagessquare rootsCalculating MachineA _ is a very _ calc

20、ulating machine. _, it can do a calculation that you could not do _.a computer computer npowerfulnin a flashnin your whole lifetime powerful In a flash in your whole lifetime Numbers: everyones languageAncient numbersAncient numbers In ancient times, people wrote numbers in many different ways. Howe

21、ver, they nearly all counted in tens.different ways of writing the number 6（在古代）（在古代）（以很多不同的方式）（以很多不同的方式）（以十为单位）（以十为单位）Numbers: everyones languageZero(0)Zero(0) 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

22、numbers. They then invented 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?（数字体系）（数字体系）（由（由组成）组成）（印度人）（印度人）（发展）（发展）（invent. v. invention n. inventor n.）9876543210Numbers: eve

23、ryones languageCalculating machines (Calculating machines (计计算工具）算工具） one of the first calculating machines was an abacus. Abacuses are fast and accurate. On the abacus, the beads on the wires stand for ones, tens, hundreds and thousands, starting from the bottom wire.（珠子（珠子 ）（代表（代表stand for ）（底部的横杆

24、）（底部的横杆）The abacus in the picture shows a number. Write it down in figures and then in words. Multiply it by zero and then add 1. What is the answer?（用数字）（用数字）（用文字）（用文字）Numbers: everyones language Modern electronic calculators can add, subtract, multiply and divide. It can also calculate percentages

25、 and square roots.（平方根）（平方根）Numbers: everyones language Computers are very powerful calculating machines. A computer can do a calculation in a flash, but you might not be able to do it in your whole lifetime.（强大的）（强大的）（做计算）（做计算）（一瞬间）（一瞬间）（能够做）（能够做）（一辈子）（一辈子）May is asking T M Li, the writer, some que

26、stions about his 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. 2 Long ago, people wrote them in many different ways. Wrote what? Numbers.3. People all count

27、 in this way. In what way? In tens.4. The Indians first invented that system of numbers. Which system of numbers? 1 to 9.5. The invention helped people write in big numbers. What invention? Zero.6. They are fast and accurate. What? Abacuses.7Computers are very powerful ones. Very powerful what? Calc

28、ulating machines.Give answers to these questions about the article.1 How did people in ancient times count in the same way? They nearly all _.2 What do the beads on the wires of an abacus stand for? The beads stand for _ starting from the bottom wire.3 What can a modern electronic calculator do? It

29、can _.counted in tensones, tens, hundreds and thousandsadd, subtract, multiply and divide.Give answers to these questions about the article.4 What else can a modern electronic calculator do ? I can also _.5 How quickly can a computer do a calculation? I can do a calculation _. calculate percentages

30、and square rootsin a flash 以不同的方式以不同的方式 数字体系数字体系 由由组成组成 电子计算器电子计算器 平方根平方根 一瞬间一瞬间 以十为单位计算以十为单位计算代表代表9 9 做运算做运算10 10 在古代在古代1 in different ways1 in different ways2 the system of numbers2 the system of numbers3 consist of= be made up of3 consist of= be made up of4 electronic calculators4 electronic calc

31、ulators5 square roots5 square roots6 in a flash6 in a flash7 count in tens7 count in tens8 stand for8 stand for9 do a calculation9 do a calculation10 in ancient times10 in ancient timesSynopsis by paragraph:P1:P1:Ancient numbers Ancient numbers In ancient times, numbers In ancient times, numbers wer

32、e written in different ways, were written in different ways, but counting was nearly but counting was nearly always in tens.always in tens.Synopsis by paragraph:P2:P2:Zero- Everyone uses the Zero- Everyone uses the number system 1 to 9 number system 1 to 9 plus 0. The system was plus 0. The system w

33、as invented by the Indians. invented by the Indians. Zero makes it easier to Zero makes it easier to write big numbers and to write big numbers and to calculate.calculate.Synopsis by paragraph:P3-5:P3-5:Calculating machines Calculating machines Descriptions of three Descriptions of three calculating

34、 machines:calculating machines: the ancient abacus,the the ancient abacus,the modern electronic calculator modern electronic calculator and the computer.and the computer. Now try a quiz about numbers. Listen to the instructions on the recording, and circle the right answer. 80 80 49 49 1717 2.66 2.6

35、6 26% 26% 2/62/6 $75 $75 75% 75% 7575o o1/8 1/8 0.75 0.75 3333 56 56 65 65 66669090o o 90% 90% 1/9 1/97 2565 3881 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 1 Whi

36、ch one of these is an even number?2 Which one of these is a fraction?3 Which one of these is a percentage?4 Which one of these is a decimal number?5 Which one of these is an odd number?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

37、 to school on foot.9 This ring costs fifty thousand dollars.10 The highest temperature today was 30 point 5 degrees.A Imperative sentencesWhen we give orders or instructions to people, we tell them to do or not to do something.We usually start the sentences with a verb.We often make instructions mor

38、e polite by starting with please.Sometimes we start with the name of the person receiving the instruction.Read the instructions belowBe quiet.Please have a seat.David, pay attention.Dont be afraid.Please do not make a noise.Alan, dont be late.Read the dialogues and complete them with imperatives and

39、 the correct form of the verbs in brackets.1 Its her birthday next week. Then _ her about the surprise party.2 How can I get to Peoples Hospital? _ along the street and _left at the lights.3 We have to finish the work in two hours. Then lets _ any time.4 _ so much noise, please. OK.5 _ out! Theres a

40、 car coming. Thanks.dont tellGoturnnot wasteDont makeLookAdd 3 and 9.Subtract 3 from 9.Multiply 3 by 9.Divide 9 by 3.B Instructions and statements about numbersTable I3 plus 9 equals/ is 12.9 minus 3 equals/ is 6.3 multiplied by 9 equals/is 27.9 divided by 3 equals/ is 3.B Instructions and statement

41、s about numbersTable II Work in pairs to work out the problems. Work in pairs to work out the problems. S1 tells S2 to do the following sums. S1 tells S2 to do the following sums. S2 listens and replies. Then check S2 listens and replies. Then check your answers together.your answers together.1 1 Ad

42、dAdd 11 11 and and 1.1.2 2 SubtractSubtract 5 5 from from 13.13.3 3 MultiplyMultiply 7 7 byby 8. 8.4 4 Divide Divide 1616 by by 4. 4.5 5 Add Add 9 9 andand 6. 6.6 6 Add Add 14 and 4 and 14 and 4 and dividedivide the the answer by 2. answer by 2.7 7 SubtractSubtract 9 from 19 and 9 from 19 and multip

43、lymultiply the answer by 3. the answer by 3.S1 11 plus 1 equals 12.11 plus 1 equals 12. 13 minus 5 equals 8.13 minus 5 equals 8. 7 multiplied7 multiplied by by 8 equals 56.8 equals 56. 16 divided16 divided by by 4 equals 44 equals 4. . 9 plus 6 equals 15.9 plus 6 equals 15. 14 plus 4 divided14 plus

44、4 divided by by 2 equals 92 equals 9. . 19 minus 9 multiplied19 minus 9 multiplied by by 3 equals 303 equals 30. .S21 Think of a number, but dont tell me what it is.2 Add 1.3 Multiply the answer by 2.4 Now add 3.5 Now multiply by 2 again.6 Now subtract 10.7 Now tell me the answer.C cardinal and ordi

45、nal numbers Say these cardinal numbers. 3 13 30 323 13 30 32 5 15 50 54 5 15 50 54 6 16 60 67 6 16 60 67 9 19 90 98 9 19 90 982 100 200 210 3752 100 200 210 375 1,000 4,189 1,000 4,189 15, 362 15, 362 100,000 100,000 C cardinal and ordinal numbers3 3 284,653284,653 two hundred and eighty-four two hu

46、ndred and eighty-four thousand six hundred and fifty-thousand six hundred and fifty-threethree 1,000,0001,000,000 one million one million 1,367,982 1,367,982 one million three hundred and one million three hundred and sixty-seven thousand nine hundred sixty-seven thousand nine hundred and eighty-two

47、and eighty-two C cardinal and ordinal numbers Say these sentences with ordinal numbers.Position in class Position in class May: 1 May: 1 May is first.May is first. Alan: 2Alan: 2Danny: 3Danny: 3June: 4June: 4Peter: 12Peter: 12Alice: 19Alice: 19Steve: 28Steve: 28C cardinal and ordinal numbers Say the

48、se decimals.3 : .3 : point threepoint three0.30.3zero point threezero point three.368.368point three six eightpoint three six eight7.1457.145seven point one four fiveseven point one four five36.3636.36thirty-six point three sixthirty-six point three sixA Talk time A1 Read these telephone numbers.2921 51432921 51432565 13512565 13512471 01222471 01222389 41672389 41672010 51002010 51002724 55662724 55662978 11212978 11212356 43992356 4399 When we say telephone When we say telephone or ID card numbers, or ID card