1. Chapter 4 (1) The world of numbers

2. chapter 4 The world of numbers 2 123 2342 63% 0.45 6.01 4.1° 2.7% 2012 1/6 3/7 123 2342 63% 0.45 6.01 4.1° 2.7% 2012 1/6 3/7 one hundred and twenty-three two thousand three hundred and forty-two sixty-three percent zero point four five six point o one four point one degree two point seven percent two thousand and twelve / two o one two one sixth three sevenths

3. 3 ordinal numbers ordinal numbers cardinal numbers cardinal numbers odd numbers odd numbers even numbers even numbers decimal numbers decimal numbers fractions fractions percentage percentage degree degree decimal degree decimal degree 80 49 2/6 0.75 17 2.66 $75 75% 1/8 0.75 33 56 65 66 90 ° 1/9 2565/2881 1.8% 18% sixtieth 15,000 Please tell me what number it is or they are as quickly as you can

4. ＋ — × ÷

5. 5 3+5 = 8 3 plus 5 is 8. 5 added to 3 is (equals) 8 Add 3 and 5, and you can get 8. If you add 3 and 5, you can get 8. 15 + 16 = 31 7 + 5 = 12 Q: How to say “4 + 12 =?” What is 4 plus 12? How much is 4 plus 12? 9 + 10 = ? 12 + 14 = ?

6. 6 12 – 3 = 9 12 – 3 = 9 12 minus 3 is (equals ) 9. 3 subtracted from 12 is (euqals) 9. 12 minus 3 is (equals ) 9. 3 subtracted from 12 is (euqals) 9. Subtract 3 from 12, and you can get 9. Subtract 3 from 12, and you can get 9. If you subtract 3 from 12, you can get 9. If you subtract 3 from 12, you can get 9. 2-2=0 15-3=12 2-2=0 15-3=12 28-12=16 44-8=36 28-12=16 44-8=36 Q: How to say “5 - 2 =?” What is 5 minus 2? What is 5 minus 2? How much is 5 minus 2 ? How much is 5 minus 2 ? 52-14=? 17-4=? 52-14=? 17-4=?

7. 7 2×3= 6 2 times 3 is (equals ) six. Two multiplied by 3 is (equals) 6 Multiply 2 by 3, and you can get 6. If you multiply 2 by 3, you can get 6. 10 × 4 = 40 5 × 3 = 15 How to say : 4× 5 =? What is 4 times 5? How much is 4 times 5? 25 × 4 = ? 15 × 7 = ?

8. chapter 4 The world of numbers 8 30÷ 6 = 5 30 divided by 6 is (equals) 5. If you divide 30 by 6, the answer is 5. you can get 5. Divide 30 by 6, and you will get 5. 20 ÷ 2 = 10 18 ÷ 3 = 6 How to say: “25 ÷ 5 =?” What is “25 divided by 5?” How much is “25 divided by 5?” 100 ÷10 =? 35 ÷ 7 =?

9. Chapter 4 (2) The world of numbers

10. Read the following words aloud

11. ancient count system consist of Indian invent develop calculate abacus bead electronic add/plus minus/subtract 古老的 计算 系统 由 … 构成 印度的；印度人 发明；创造 发展 计算；估算 算盘 有孔的珠子 电子的 加 减

12. multiply / times divide percentage square root in a flash stand for separately instruction accurate international decision 乘，使相乘 某数除以某数，除以 百分比，百分率 平方根 一瞬间 代表 分别地 指导，指令 准确无误的，精确的 国际的 决定（ n. ）

13. ＋ — × ÷

14. 12+13= ? Q: What is 12 plus 13? How much is 12 plus 13? How much is 12 added to 13? A: 12 plus 13 is 25. Add 12 to 13, you can get 25. If you add 12 to 13, you’ll get 25. Adding 12 to 13 is (equals) 25. 12 added to 13 is (equals) 25 52-14=? Q: What is 52minus 14? How much is 14 subtracted from 52? A: 52 minus 14 is ( equals) 38.) Subtract 14 from 52, and you can get 38. If you subtract 14 from 52, you will get 38. Subtracting 14 from 52 is 38. 14 subtracted from 52 is 38.

15. 35 ÷ 7 =? Q: How much is 35 divided by 7 ? What is 35 divided by 7 ? A: 35 divided by 7 is 5. Divide 35 by 7, and you can get 5. If you divide 35 by 7, you will get 5. Dividing 35 by 7 is 5. 10 × 4 = ? Q: How much is 10 times 4? What’s 10 times 4? A: Ten times four is 40. Multiply 10 by 4, and you can get 40. If you multiply 10 by 4, you will get 40. Multiplying 10 by 4 is 40. 10 multiplied by 4 is 40.

16. chapter 4 The world of numbers 16 plus (+) plus (+) add add (+) minus (-) minus (-) subtract subtract (-) multiply (x) multiply (x) times times (x) divide ( ÷ ) divide ( ÷ ) equals (=) equals (=) is (=) is (=) 72+272 105 – 22 10000x3.6 1440÷12 0.92x18.18 0.504÷0.12 =344 =83 =36000 =120 =16.7256 =4.2

17. Numbers : Everyone’s language

19. 245×619÷35 － 891 ＋ 521= ？ Can you calculate it in a flash? No, we can’t. But we can do it by using calculating machines calculating machines

20. How many languages do you know? Everyone knows at least two – his or her own language and the international language of numbers. How many languages do you know? Everyone knows at least two – his or her own language and the international language of numbers. Numbers: everyone’s language （他或她自己 的语言） at least : not less than

21. chapter 4 The world of numbers 21 Ancient numbers In ancient times, people wrote numbers in many different ways. However, they nearly all counted in tens. different ways of writing the number 6 Ancient times Ancient money Ancient house Ancient city Ancient building (Once upon a time ) almost （以十为单位）

22. chapter 4 The world of numbers 22 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 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? Our class consits of 44 students Our class is made up of 44 students. His breakfast __ ___ ___ ___dry bread and tea. _____ _____ invent. v. invention n. inventor n. is made up of consists of （数字体系） 9,876,543,210

23. chapter 4 The world of numbers 23 Calculating machines ( 计算工具） 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. an abacus stand for: represent

24. chapter 4 The world of numbers 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? （以单词的形式） （以数字的形式） 2,597 2597x0+1=? Pay attention to the following: in figures in words in different ways in English / in Chinese in ink / in oil two thousand five hundred and ninety-seven

25. chapter 4 The world of numbers 25 Modern electronic calculators can add, subtract, multiply and divide. It can also calculate percentages and square roots. （平方根） calculator n. calculating adj. calculate v an electronic calculator a calculating machine

26. chapter 4 The world of numbers 26 Computers are very powerful calculating machines. A computer can do a calculation in a flash. (in a second/very quickly in a very short time )

27. May asks T M Li, the writer, some questions about his article on numbers. His answers are not always clear. Read the article and make Li’s answers clearer. Write one word in each blank. May asks T M Li, the writer, some questions about his article on numbers. His answers are not always clear. Read the article and make Li’s answers clearer. Write one word in each blank. 1 Every one knows it. Knows what? The of. Languagenumbers

28. 2 Long ago, people wrote them in many different ways. 2 Long ago, people wrote them in many different ways. Wrote what? Wrote what?.. 3. People all count in this way. 3. People all count in this way. In what way? In what way?.. 4. The Indians invented that system of numbers. 4. The Indians invented that system of numbers. Which system of numbers? Which system of numbers? The system. The system. Numbers. In tens 1 to 9

29. 5 The invention helped people write in big numbers. 5 The invention helped people write in big numbers. What invention? What invention? The invention of the. The invention of the. 6 They are fast and accurate. 6 They are fast and accurate. What? What?.. 7 Computers are very powerful ones. 7 Computers are very powerful ones. Very powerful what? Very powerful what?.. zero Abacuses Calculating machines

30. E Read and think Give answers to these questions about the article. Work in pairs. 1 – How did people in ancient times count in the same way? 1 – How did people in ancient times count in the same way? -- They nearly all. -- They nearly all. 2 – What do the beads on the wires of an abacus stand for? 2 – What do the beads on the wires of an abacus stand for? -- The beads stand for, -- The beads stand for,, starting from bottom wire. 3 – What can a modern electronic calculator do? 3 – What can a modern electronic calculator do? -- It can. counted in tens. ones, tens hundreds and thousands add, subtract, multiply and divide

31. E Read and think Give answers to these questions about the article. Work in pairs. 4 – What else can a modern electronic calculator do? 4 – What else can a modern electronic calculator do? -- It can also. -- It can also.. 5 – How quickly can a computer do a calculation? 5 – How quickly can a computer do a calculation? -- It can do a calculation. -- It can do a calculation. calculate percentages and square roots in a flash

32. Numbers : Numbers : Everyone’s language Everyone’s language

33. We can use them to calculate. an electronic calculator a computer an abacus Calculating machines

34. an electronic calculator add subtract multiply divide percentage square root Calculating Machine

35. beads wires 5,7 2 4 — thousands — hundreds — tens — ones an abacus one of the first calculating machines one of the first calculating machines accurate and fast accurate and fast

36. Calculating Machine an electronic calculator A: What can an electronic calculator do? B: It can _________, _________, _________ and _________. A: What else can it do? B: It can calculate ___________ and ___________. addsubtrac t multipl y divide percentage s square roots

37. Calculating Machine A ________ is a very _______ calculating machine. It can do a calculation in__________. a computer computer powerful powerful in a flash in a flash powerful powerful a flash a flash

38. 1.Listening and reading (15 minutes.) 2. p68-69 ， P71-72 数词专练单选 3. 背诵并复习课文内容，明天默写

39. Numbers : Numbers : Everyone’s language Everyone’s language

40. Fill the blanks according to the text

41. How many ______ do you know? Everyone knows _______ two – his or her ___ language and the ___________ language of numbers. _____ numbers In ancient times, people wrote ______ in many different ____. However, they ____ all counted in ____. languages at least own international Ancient numbers ways nearly tens

42. The system of numbers today ______ the numbers from 1 to 9 and 0(zero). The ______ first invented and developed the 1 to 9 ______ of numbers. They then _____ the zero. The invention of the zero ____ people write ______ numbers and calculate more _____. Now use each of these ___ numbers once to _____ the biggest ______. What is it? consists of Indians system invented helped big easily ten write number

43. Calculating machines ( 计算工具） One of the first ______ machines was an _____. Abacuses are ____ and accurate. ____the abacus, the _____ on the wires ______ ones, tens, hundreds and thousands, ____ from the bottom wire. calculating abacus fast On beads stand for starting

44. The ______in the picture shows a number. _____it down in _____ and then in ____. Multiply it __ zero and then ___ 1. What is the answer? Modern ________ calculators ______ add, subtract, multiply____ divide. It can _____calculate percentages and______ roots. abacus Write figures wordsby add electronic and also square can

45. Computers ___ very powerful ______ machines. A computer ___ do a calculation in a _____. are calculating can flash

46. 46 Complete the short passage: Everyone knows (1) two languages---his or her own language and the (2) language of numbers. In (3) times, nearly all numbers were Counted in tens.The(4) first (5) ________ and (6) the(7) of numbers today. It (8)______ ___ the numbers from 1 to 9 and 0. An abacus is fast and (9).It was one of the first (10) machines. On it, the beads on the wire (11) ones, tens, hundreds,and thousands, starting from the (12) wire.Modern (13) ______ calculators can add, subtract, multiply and divide. Computers are very(14) calculating machines. They can do calculations in a (15). at least international ancient Indians invented developedsystem accurate calculating stand for bottom electronic powerful flash consists of

47. Competition 1111 2222 3333 4444 5555 6666 7777 8888

48. Who first invented and developed the 1to 9 system of numbers? The Indians. The Indians.

49. What can an electronic calculator do? It can add, subtract, multiply and divide. It can also calculate percentages and square roots. It can add, subtract, multiply and divide. It can also calculate percentages and square roots.

50. How did people write numbers in ancient times? They wrote numbers in many different ways. They wrote numbers in many different ways.

51. How long can a computer do a calculation? In a flash. In a flash.

52. What did the invention of the zero help people do? It helped people write big numbers and calculate more easily. It helped people write big numbers and calculate more easily.

53. How did people in ancient times count in the same way? They nearly all counted in tens. They nearly all counted in tens.

54. What do the beads on the wires stand for? They stand for ones, tens, hundreds, thousands and so on. They stand for ones, tens, hundreds, thousands and so on.

55. How many languages does everyone at least know? Two– his or her own language and the international language of numbers. Two– his or her own language and the international language of numbers.

56. Shakuntala Devi a computer

57. 夏琨塔拉‧大卫（ Shakuntala Devi ） 1939 年 11 月 4 日出生於印度的邦加罗尔（ Bangalore ）， 她是印度的数学家，常被称誉为「人类计算器」 (Human Computer) 、 「世上最聪明的女人」。 她曾在全球各大学接受测试， 现场示范其最著名的特殊能力： 在 28 秒内计算出两个任意 13 位数的乘积, 这项成就让大卫 女士名列金氏世界记录

58. Some people call the brain a living computer Is a human brain a more powerful calculator than a computer? The following story may give an answer. Shakuntala Devi is a lady from India with an amazing brain. She can calculate like lightning. In America, Shakuntala and a very powerful computer were given this problem to solve. Shakuntala's brain took fifty seconds to find the answer. The computer took a minute. However, before the computer could begin calculating, someone had to program it with instructions, and that took many hours. No one had to program Shakuntala!

59. More information about numbers

60. For odd numbers, seven implies( 暗示 ) anger and abandon （丢弃）, but nine, sometimes means longevity( 长寿 )and eternity （永恒）. Based on these notions( 观念 ), it is the fashion for young lovers to send roses. One rose represents that 'you are my only love'; two, 'only we two in the world'; three, the three moving words 'I love you ' ; and nine, 'everlasting love'.

61. The lucky-number has become increasingly popular in daily life of modern sociality. Because some people believe that the “ Lucky Numbers" can bring them good luck and great fortune. They would like to pay twice or many times more of the usual price for a “ Lucky ” telephone number or a car plate number. For instance, the so-called lucky number “ 8 ” is widely used now because it is sounded like “ getting rich ” in Chinese and is believed to bring good fortune, but the number four means death. Some people believe lucky numbers so deeply that they will afford a telephone with numbers without four and others which is bad in their mind.

62. Talking about the advantages and disadvantages of different kinds of calculating machines.

63. abacus electronic calculator computer