Chapter 4 The world of numbers1. ReadingReadingListeningListeningLanguageLanguageSpeakingSpeakingWritingWriting2.A What do you know about?We all use numbers in our daily life. Numbers are an international language. 3.Lets learn the language of numbers!1. a decimal number( 小数 ) 0.65 (zero point six five/ zero point sixty-five) 8.08 (eight point o eight.)Please read the following:7.65, 3.12, 0.09, 86.204.3. even numbers (偶数) 300, 42 a pair of even numbers 4. zero (零) 2. odd numbers (偶数) 25, 11 a pair of odd numbers5.1/2 : one half 2/3 : two thirds1/4 : a quarter1/10: one tenth5. a fraction (分数） Please read the following: 3/8, 6/12, 1/76. 38 3 plus 5 is 8. Add 3 and 5, you can get 8. Q: How to say “4 + 12 =?” What is 4 plus 12? 6. plus , add ( 加） Please read the following:15 + 16 = 41 9 + 10 = ?7. 12 3 = 9 12 minus 3 is 9.Subtract 3 from 12, you can get 9.Q: How to say “5 - 2 =?” What is 5 minus 2? Please read the following: 2-2=0 17-4=?7 minus (减，减号，负号） subtract (减)8. 2 times 3 is six. Multiply 2 by 3, you can get 6. Please read the following: 10 4 = 40 5 3 = 158 multiply; times (乘)9. 30 6 = 5 Divide 30 by 6 is 5. 30 divided by 6 is 5. Please read the following: 20 2 = 10 18 3 = 6 9 divide (除)10.10. 45a number showing degrees degree: 度，度数11. 60 a percentage (百分数) sixty percent 12. equals / is11.Match the words with the pictures, signs and numbers.defghijkl1 a decimal number4 zero11 a pair ofeven numbers8 divide5 add, plus6 subtract; minus7 multiply, times12 equals9 a numbershowing degrees10 a percentage2 a pair of odd numbers3 a fraction12. 1 invent: make for the first time 2 system: group of things/ parts that work together 3 especially: 4. at least: 5 international: used by/ connected with more than one country/ nation 6 ancient: very old 7 however: but,13. 8 nearly: almost 9 count: 10 consist of: be made up of sth. 11 India: 12. develop: grow bigger and/ or better 13 accurate: with no mistakes 14 bead:14. 15 wire: 16 stand for: 17 bottom: 18 figure 19 electronic: using electrons for power 20 powerful: strong 21. in a flash: 15. 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（他或她自己的语言）16. 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（在古代）（以很多不同的方式）（以十为单位）17. 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?（数字体系）（invent. v. invention n. inventor n.）18. 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.（底部的横杆）（算盘）19. 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）20. Modern electronic calculators can add, subtract, multiply and divide. It can also calculate percentages and square roots.（平方根）（calculator n. calculate v. calculating adj.）21. Computers are very powerful calculating machines. A puter can do a calculation in a flash.（做次计算）（一瞬间）22. 1 ancient: many many years ago (a) 2 consists of: includes (b) 3 invented: 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.23. A B 1 international a grew bigger or stronger 2 system b a group of things working 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.24. 1 A calculating machine using wires and heads. 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. calculatorputerabacus25. 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 Lis answers clearer. Write one word in each blank. 1 Every one knows it. Knows what? The Language of numbers.26. 2 Long ago, people wrote them in many different ways. Wrote what? Numbers. 3. People all count in this way. In what way? In tens. 4. The Indians invented that system of numbers. Which system of numbers? The 1 to 9 system.27. 5 The invention helped people write in big numbers. What invention? The invention of the zero. 6 They are fast and accurate. What? Abacuse。