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课件32张PPT。 Numbers :
Everyone’s languageQuizWe should call if there is a fire in China.1193
4About of the surface of
the Earth is covered with water.QuizYao Ming is
meters tall. 2.26QuizThe normal temperature of human beings is degrees . 37Quiz20Our astronaut Zhai Zhigang stayed outside
in the space for about minutes.QuizChina held a military parade to celebrate the anniversary of the victory of World War Ⅱ?Quiz70thnumbersWhat can numbers be?heightweighttimedatepricemoneybus numberclassgradepostcoderoom numberfamily membersarea…Numbers are everyone’s language.Numbers are international language.These are machines to add, subtract, multiply, divide./'k?lkjule?t/ calculatean electronic calculator/'k?lkjule?t?(r)//'?b?k?s/an abacus＋ － × ÷ B. ＋ × ÷ －
C.－ × ＋ ÷ D. × ÷ ＋ －So we call them ________________ machines.This is a machine to wash. So we call it a washing machine.These are machines to__________.calculatingcalculate
Where there is a need, there is an___________.People needed to count.
People needed to write any number from the biggest to the smallest. People needed to calculate fast and correctly.zeronumberscalculating machines3 inventions:3 needs:invention6Ancient numbers
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 numbers In ancient times, people wrote numbers in _________ ways, but counted in _______________ way.different the same
ZeroMost 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.0Zero made _______________
___________ with numbers from 1 to 9. We can write any number____________
___________________. Zero also
_______________
_______________.Zero made it easier to _______ big numbers. writemade it easier to calculate from the
biggest to the smallestthe system of numbers
Because of you
You looks like the sun
You looks like the/a ___________
You makes me bright
You light the way for me
Because of you
It was easier to ______________
Because of you
We can____________________
Because of you
…
Pair workcalculating machinesCalculating machines
Calculating machinesOne 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.calculating machinesCalculating machinesFind the number that, when it is multiplied 23 times by itself, gives this answer:
916748676920039158098660927585380162483106680144308622407126516427934657040867096593279205767480806790022783016354924852380335745316935111903596577547340075681688305620821016129132845546805780158806771
Some people call the brain a living computer. Is a human brain a more powerful calculator than a computer? The following story may give an answer.
Shakuntala Devi is a lady from India with an amazing brain. Shakuntala and a very powerful computer were given this problem to solve.
Shakuntala’s brain took fifty seconds to find the answer, like lightning. The computer took a minute. However, someone had to first program the computer with instructions, and that took many hours. No one had to program Shakuntala!
VSI am a calculating machine.I am a calculating machine.I am a lady from India.I am a lady from India.I’m very powerful.I’m very powerful.I have an amazing brain.I have an amazing brain.I only spent 50 seconds finding the answer.I only spent 50 seconds finding the answer.I only spent 1 minute finding the answer.I only spent 1 minute finding the answer.Someone had to program me.Someone had to program me.No one had to program me.No one had to program me.A record of the competitionpowerfulcalculatinga lady from India
with an amazing
brainSome one
__________
__________.No one had
to program
her.1 minute50
secondshad to
program itThere was a competition between …It is about meters wide on the top.It is over kilometers long.It has a long history of more than years.6.521,1962000Make a guess
To ChinaconsolidationTalk about the need and invention of humans in the future.
Complete Workbook 8A, pages 31, 37 and 38.The maglev train can run at the
speed of ________ an hour.kilometers431Quiz About of your body consists of ______. 70%waterQuiz
Let’s have a talk!I am a lady from India.I am a calculating machine.I only spent 1 minute finding the answer.I only spent 50 seconds finding the answer.I’m very powerful.I have an amazing brain.Someone had to program me.No one had to program me.

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