an animalscount,Hi?
My cat can.
How do you know,Hi?
I asked "What is6 minus 6" andit said nothing.
Numbers:everyone'slanguage.
aHow manylanguages do youknow?
Everyone knowsat least two--his or her ownlanguage and theinternationallanguage ofnumbers.
Ancient numbers
In ancienttimes,peoplewrote numbers inmany differentways.
However,theynearly allcounted in tens.
Zero
The system ofnumbers todayconsists of thenumbers from 1to 9 and 0(zero).
The Indiansfirst inventedand developedthe 1 to 9system ofnumbers.
They theninvented thezero.
The invention ofzero helpedpeople write bignumbers andcalculate moreeasily.
Whit these tennumbers,we canwrite any numberfrom the biggestto the smallest.
Calculatingmachines
One of the firstcalculatingmachines was theabacus.
Abacuses arefast andaccurate.
On the abacus,the beads on thewires representones,tens,hundreds andthousands,starting fromthe bottom wire.
The abacus inthe pictureshows a number.
Write it down infigures,and thenin words.
Multiply it byzero and thenadd 1.What isthe answer?
Modernelectroniccalculators canadd,subtract,multiply anddivide.
They can alsocalculatepercentages andsquare roots.
Computers arevery powerfulcalculatingmachines.
A computer cando millions ofcalculations ina flash.
Cardinal andordinal numbers
3 three5 five6 six9 nine
13 thirteen15 fifteen16 sixteen19 nineteen
30 thirty50 fifty60 sixty90 ninety
32 thirty-two54 fifty-four67 sixty-seven98 ninety-eight
100 one hundred200 two hundred375three hundredand seventy-five1,000one thousand
4,189four thousandone hundred andeighty-nine
15,362fifteen thousandthree hundredand sixty-two
100,000one hundredthousand
284,653two hundred andeighty-fourthousand sixhundred andfifty-three
1,000,000one million
5,367,982five millionthree hundredand sixty-seventhousand ninehundred andeighty-two
We use ordinalnumber to showthe order ofthings.
We form mostordinals byadding -th tothe cardinalnumbers.
There are alsoexceptions,likefirst,second andthird.
1st first2nd second3rd third5th fifth
8th eighth9th ninth12th twelfth13th thirteenth
20thtwentieth21sttwenty-first22ndtwenty-second23thtwenty-second100th hundredth
t10
0May is callingher friend,Rita.Read theirconversation andpractise it.
Then work inpairs to checkthe otherhomeworkproblems inMay's notebook.
RITA:2890 6521(two eight ninezero,six fivetwo one).
MAY:Hello,Rita.This is May.
RITA:Hi,May.Whatcan I do foryou?
MAY:I made amistake with myhomework,Ithink.Can Icheck it withyou?
RITA:Sure.Whichone?
MAY:Number 5.Isit 0.92 (zeropoint nine two)times 18.18(eighteen pointone eight)?
RITA:No,itshould be 0.92times 18.16(eighteen pointone six).
MAY:Thanks,Rita.See youtomorrow.Bye.
RITA:Goodbye,May.
Trafficaccidents
Li Jie askedOfficer Chenabout trafficaccidents.Thenshe drew a linegraph.
Read theirconversationbelow and writethe figures onthe graph.
LI JIE:How manytrafficaccidents werethere in twothousand and twoin our city?
CHEN:Threethousand sixhundred andninety-one.
LI JIE:What wasthe number intwo thousand andthree?
CHEN:Threethousand sevenhundred andforty-eight.
LI JIE:Whatabout in twothousand andfour?
CHEN:Threethousand sixhundred andforty-four.
LI JIE:And twothousand andfive?
CHEN:Threethousand sevenhundred andtwenty-nine.
LI JIE:Whatabout in twothousand andsix?
CHEN:Threethousand sixhundred andthirty-nine.
LI JIE:Thankyou,Mr Chen.
CHEN:Not at all.
t2
Read about theinvention ofclocks andwatches.
Clocks andwatches
Now,we can telltime veryaccurately,butbefore theinvention ofclocks,it wasvery difficult.
People used theposition of thesun in the skyto tell time inancient times,but it wasimpossible to doit on cloudydays or atnight.
In 1099,Su Songinvented thefirst mechanicalclock in China.
195 years later,in 1283,the British inventedthe first clockin Europe.
Then 67 years later,in 1350,the Germansinvented thealarm clock.
The Italiansinvented thefirst watch in1462.
Early watcheswere differentfrom today's intwo ways.First,they only hadone hand--thehour hand.
Second,you hadto keep them inyour pocket.People calledthem 'pocketclocks'.
The first wristwatches camefrom Switzerland328 years afterthe first pocketclock,
but they did notbecome popularfor a hundredyears.
Digital clocksand watches camefrom the UnitedStates and arethe latestinvention intime-keeping.
Shops started tosell them in1971.