Chapter Four,Oxford English 8A,Ancient numbers,Greek,Egyptian,(希腊的; 希腊人; 希腊语),(埃及的;埃及人),Roman,=1 =5 =10 L=50 C= 100 D= 500 M=1000,III=3， =4， =6，=19， =20，L= MCMC=,1980,45,Chinese,壹 贰 叁 肆 伍 陆 柒 捌 玖 拾 佰 仟 万,0,Who invented these numbers?,2 3 4 5 6 7 8 9,Who invented “zero”?,Why was it a very important invention?,Indian,Arabian number,It made it easier to write big numbers and to calculate.,30%,a protractor,a pair of compasses,What are these?,a decimal numberadj. 小数的, n.小数,0.824,a pair of odd numberadj. 奇数的, 单数的, 不成对的,51 89,a fraction n. 分数,a pair of even numberadj. 偶数的,32 158,+,add ; plus,-,subtract , minus,x,multiply, times,divide,=,equals,Signs,Calculating machines,an abacus,one of the first calculating machines,fast and accurate,used today,electronic calculator,a modern calculating machine,can add , subtract, multiply and divide,can calculate percentages and square roots,Why do you often use it?,computer,a very powerful calculating machine,can do a calculation that you could not do in your whole lifetime,brain,living computer,Which is more powerful?,Shakuntala Devi,7 686 369 774 870 2 465 099 745 779 =?,18 947 668 177 995 426 462 773 730,28 seconds,How long did it take her to work out this problem?,an Indian lady,916748676920039158098660927585380162483106680144308622407126516427934657040867096593279205767480806790022783016354924852380335745316935111903596577547340075681688305620821016129132845546805780158806771,How long did it take to solve this problem?,a = ?,Shakuntala Devi: seconds,Computer : seconds,546,372,891,50,60,like lighting,in a flash,1. Say something about numbers.,2. The development of calculating machines.,Free Talk,+,add ; plus,-,18 + 26 = 44,subtract , minus,87 - 24 = 63,=,equals,A: Add 18 and 26,B:18 plus 26 is/equals 44,A: Subtract 24 from 87,B: 87 minus 24 is/equals 63,60 + 34 = 94,35 20 = 15,Pair work,x,multiply, times,40 x 5 =200,divide,90 30 = 3,A: Multiply 40 by 5,B: 40 multiplied by 5 is 200,A: Divide 90 by 30 .,B: 90 divided by 30 equals 3,20 x 5 = 10080 16 = 5,Pair work,What is it?,A: Think of a number. But dont tell me what it is. Add 1. Multiply the answer by 2. Now add 3. Now multiply by 2 again. Now subtract 10. Now tell me the answer. B:A:,Work in pair,48,12,2,a,b,c,i,ii,iii,4,5,8,9,3,1,6,7,Read these numbers,1 mile = 1.609 km,one point six o nine,40% of our classmates are girls.,forty percent,five sixths,His telephone number is 86765434.,I was born on January 18,1967.,The Changjiang River is 6,378 kilometers long.,32,805,041,thirty-two million eighty hundred and five thousand and forty-one,1,306,313,812,one billion three hundred and six million three hundred and thirteen thousand eight hundred and twelve,Say these cardinal numbers,1950,one thousand nine hundred and fifty,one nine five zero,nineteen fifty,1. 72+27 2. 105-22 3.10,000 x 36 4. 1,440 12 5. 0.92 x 18.18 6. 0.504 0.12,_,1. 72+272 2. 150-22 3.10,000 x 3.6 4. 1,440 120 5. 0.92 x 18.16 6. 0.504 1.12,Work in pair,￥35，000,Fellow students Mr Tang has given our school a gift of ￥35,000. Our group thinks we should buy these three things. First _. This will cost about ￥ _ Second, _. This will cost about ￥ _. Third ,_ This will cost about ￥ _. Have you got any questions?,We should buy new equipment for gym,5,000,We would like to buy some more books for the library.,10,000,We should buy some computers,20,000,a traffic accident,3,748,3,644,3,729,3,639,The graph shows that there _ in 1996 in our city. In _, the number _ to _ and _ to _ in _. In _ the number _again to _. It _to _in _,were 3,691 traffic accidents,1997,rose,3,748,fell,3,644,1998,1999,rose,3,729,fell,3,639,2,000,Traffic accidents 1996-2000,Fahrenheit 华伦海特,Anders Celsius 摄尔西乌斯,18世纪初德国仪器制造家华伦海特发明了一个玻璃水银柱温度计，柱上刻有度数，当水银因热而膨胀时，可以读出柱高的增加数。华伦海特用冰与食盐的混合物所能得出的最低温度作为他的刻度的零度。按他的刻度，水的水的结冰读数为32，水的沸腾读数为212，两者距离为180。这种刻度很快得到普遍应用，特别是在气象工作方面，因其刻度细，有利于气象测量。1730年法国博物学家列奥米尔建议把结冰与沸腾之间的距离分成80，这就是列氏温标。不久以后瑞典天文学家摄尔西乌斯提议把两者中间的距离分成100。18世纪末法国国民公会采用摄氏刻度作为公制的一部分，现在大多数国家都使用这种刻度的温度计。,30o,60o,90o,thirty degrees,sixty degrees,