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课件网) 2 Numbers Reading Amazing things B2 We all use numbers in our daily life. Numbers are an international language. What do you know about the language of numbers Try this quiz. Match the words with the signs and numbers. 1 a decimal number 7 add; plus 2 equals 8 subtract; minus 3 a pair of odd numbers 9 multiply 4 a pair of even numbers 10 divide 5 a fraction 11 a number showing degrees 6 zero 12 a percentage 8-8 1 2 3 4 5 6 7 8 9 10 11 12 /d 'ɡri:/ /p 'sent / 8-4 calculate (v.) find the answer by using maths /'k lkjule t/ Can you calculate how much the holiday will cost calculator (n.) an electronic machine that adds, subtracts, multiplies and divides /'k lkjule t (r)/ ＋ － × ÷ add subtract multiply divide /s b'tr kt/ /'m lt pla / /d 'va d/ B Now, look at the title, the introduction, the headings and the pictures. Then on the list below, tick ( ) the things you think the article may tell you. Long ago, there were different ways of writing numbers. Zero is not a number. Zero is an especially important number. Machines make it easier for us to calculate. Your brain may calculate better than a computer. Your brain is an important part of your body. 8-1 B Read the passage. How many languages do you know Everyone knows at least two—his or her own language and the international language of numbers. 16-7 In ancient times, people wrote numbers in many different ways, as these pictures of the number 6 show. However, they nearly all counted in the same way—in tens. Ancient numbers ancient people 十进制 ancient civilization Zero Most of us use the system of numbers with numbers from 1 to 9 and 0 (zero). With these ten numbers, we can write any number from the biggest to the smallest. The Indians first invented and developed the 1 to 9 system of numbers. They then invented the zero. This was a very important invention because it made it easier to write big numbers and to calculate. Calculating machines abacus electronic calculator computer fast and accurate do all kinds of calculations powerful 16-9 Calculating machines One of the first calculating machines was an abacus. Abacuses are so fast and accurate that people still use them today. A modern electronic calculator can add, subtract, multiply and divide. It can also calculate percentages and square roots. Computers are very powerful calculating machines. In a flash, a computer can do a calculation that you could not do in your whole lifetime. Brain against computer Find the number that, when it is multiplied 23 times by itself, gives this answer: 916748676920039158098660927585380162483106680144308622407126516427934657040867096593279205767480806790022783016354924852380335745316935111903596577547340075681688305620821016129132845546805780158806771 给出一个201位的数，算出它的23次方根 Brain against computer Some people call the brain a living computer. Is a human brain a more powerful calculator than a computer The following story may give ... ...
