8AChapter4NumbersPPT课件

1、Chapter 4 Numbers,Match the words with the meanings,?,A. very surprising,?,B. grew bigger,?,?,C. a group of things that,?,work together,?,D. to use numbers to find,?,answers,?,E. strong,?,?,F. to give orders to a,?,computer,?,?,G. to find an answer to,?,H. used by more than,?,?,one country or nation

2、,?,i. mean, stand for,?,?,J. using electrons for,power,?,1. international,2. a system,3. developed,4. to calculate,5. represent,6. electronic,7. powerful,8. amazing,9.To solve,10. to program,?,1.How did people write numbers in,ancient times? How did people count ?,?,2.Who invented the system of numb

3、ers?,Is it very useful ?,?,3.Do people still use abacuses,today? Why ?,Questions,?,4. What can a modern calculator do?,?,5.Can Shekuntala calculate faster than a,computer? How long did she take? How,long did a computer take?,?,6. Do you know our school telephone,number? What is it?,?,7.When is your

4、birthday?,?,8. How many girls are there in our class?,What is the percentage?,?,9.If we add 24 and 31, what is the,answer?,?,10. If we subtract 6 from 30, what is the,answer?,?,11.If we multiply 6 by 7, what is the,answer?,?,12. If we divide 3 from 36, what is the,Lets calculate,?,Instructions /orders,?,Answers,(1)Add 11 and 1.,(2)Subtract 5 from 13.,(3)Multiply 7 by 8.,(4)Divide 16 by 4.,(1)11,plus,1,equals,12.,(2)13,minus,5,equals,8.,(3)7,multiplied by,8,equals,56.,(4)16,divided by,4,equals,4.,Homework,?,1. Th