《牛津深版英语七上7.4The world of numbersppt课件之三》由会员分享，可在线阅读，更多相关《牛津深版英语七上7.4The world of numbersppt课件之三（23页珍藏版）》请在金锄头文库上搜索。
1、Chapter 4Grade Seven初一年级组初一年级组NumbersLanguage pointsreading practiceCalculating machines A What do you know about?1 a decimal numbers2 a pair of odd numbers 3 a fraction4 zero5 add;plus6 subtract;minus7 mutiply; times 8 divide9 a number showing degrees10 a percentage11 a pair of even numbers12 equal
2、sA +B 0C 5/8D E =F 13 45G 8 210H 90I J 0.82 K 45%L Numbers, Everyones Language24561935891521=?Calculating Machineone of the first one of the first calculating machines calculating machines accurateaccurate and fastand fastrepresentrepresentbeadswires5,7 2 4 thousandsthousands hundredshundreds tenste
3、ns onesonesan abacusan abacusCalculating Machinean abacusan abacusCalculating Machinean electronic calculatoran electronic calculatoraddsubtractmultiply divide percentagesquare rootcalculatecalculateCalculating Machinean electronic calculatoran electronic calculatorA: What can an electronic calculat
4、or A: What can an electronic calculator do?do?B: It can _, _, B: It can _, _, _ and _._ and _.A: What else can it do?A: What else can it do?B: It can calculate _ and B: It can calculate _ and _._.addsubtractmultiplydividepercentagessquare rootsCalculating Machinean electronic calculatoran electronic
5、 calculatorA: What can _ do?A: What can _ do?B: It _.B: It _.A: What else can it do?A: What else can it do?B: It _.B: It _.Calculating Machinepowerfula flashin your whole lifetimea computerCalculating MachineA _ is a very _ calculating A _ is a very _ calculating machine. In _, it can do a calculati
6、on machine. In _, it can do a calculation that you could not do _that you could not do _._.a computer computer powerful computer powerful a flash a flash in your whole in your wholelifetimelifetime powerfulpowerful a flasha flash in your whole lifetimein your whole lifetimen. n. v. v. a. a. abacusab
7、acusrepresentrepresentaccurateaccuratebeadbeadaddaddelectronicelectronicwirewiresubtractsubtractpowerfulpowerfulpercentagepercentagemultiplymultiplyamazingamazingsquare root square root dividedividecalculator calculator calculatecalculatecalculationcalculationprogramprogramflashflashlifetimelifetime
8、brainbraininstructioninstructionRead the textCompetitionAnswer the questions12345678Why do people still use abacuses today?Because they are accurate and fast.What can an electronic calculator do?It can add, subtract, multiply and divide. It can also calculate percentages and square roots.How fast ca
9、n Shakuntala Devi calculate?She can calculate like lightning.How long can a computer do a calculation?In a flash.How long did the computer take to solve the difficult problem?A minute.What should people do to make computers calculate?People have to_ _. program them with instructionsWhat do the beads on the wires represent?They represent _ _ ones, tens, hundreds, thousands and so on.
