decimals是什么意思,decimals的意思翻译、用法、同义词、，Fractions

大家好，今天小编来为大家解答decimals是什么意思,decimals的意思翻译、用法、同义词、这个问题，Fractions很多人还不知道，现在让我们一起来看看吧！

Inthelastsectionwelearnedoneofthemostimportantthingsofourfractions.Welearnedthatthey’renumbersthatwrittenlikedivisionproblems.Wealsoknowthatfractionscanbeusedtorepresentsmallerpartsofthings.

Sincethefractionsaredivisionproblems,wecangoaheadanddothedivisionandgetananswer.Andthatanswerwillbearegularnumber.That’sthevalueofthefraction.

Let’slookatthisfractionforanexample:tenfifth(10/5).That’sthesameasthedivisionproblem:10dividedby5.Nowyouknowthat10dividedby5is2,sothevalueofthisfractionis2.

Sowhat’sthedeal?Thevalue2doesn’tlooklikeasmallerpartofsomething.

Here’sthedeal.Ifthetopnumberofafractionisgreaterthanthebottomnumber,thenthevalueofthefractionwillbegreaterthan1.Butifthetopnumberissmallerthanthebottomnumber,thenthevalueofthefractionwillbesmallerthan1.

Butifwedivideasmallernumberbyabiggernumberandgetavaluethatissmallerthan1,howwegonnawriteitdownlikearegularnumber?

Wecanwritevaluethatissmallerthan1byusingsomethingcalleddecimalnumbers.

Tounderstandhowdecimalnumberswork,let’sfirstreviewhowwewriteregularnumbersthatdon’tinvovlefractions.Wecallthosenumbers“wholenumbers”.

Weusewholenumberswhenwecountthingsandcountingthingisveryimportantinmath.Thesystemwecountthingswithisbasedonthenumber“10”.Infactit’scalled“Base10”.Andituseswhatwecalled“Powersoften”asthegroupsorbuildingblocksthatwecountwith.

It’sprobablynosurprisethatthefirstbuildingblocksis“1”.Andwecangetbiggerbuildingblocksjustbymultiplyingby10.Soournextbuildingblockis1x10or10.Andtheoneafterthatis10x10or100.Andtheoneafterthatis100x10or1000.AndIcankeeponmultiplyingby10andgetbiggerandbiggerbuildingblocksbutjuststopby1000fornow.

SowhatamIgoingtodowiththese“powersoften”?Well,likeIsaidthey’rethebuildingblocksofourcountingsystem.SoI’mgonnacountwiththem.ButbeforeIdothat,Ishouldmentiontwomorethingsthatournumbersystemneedsbesidesthesebuildingblocks.Thosetwothingsaredigitsandnumberplaces.

Digitsarejust10symbolsweuseforcounting.

Numberplacesarelikelittleimaginaryboxesthatcanholdjustonedigitatatime.

Weuseonenumberplaceforeachofourbuildingblockstocounthowmanyofeachofthemwehave.Forexample,let’ssaywehave200s.Ijustputa“2”inthenumberplacethatcountshowmanyhundredsIhave.Andlet’ssayIhavefive10s,thenIputafiveinthenumberplacethatcountstens.AndIalsohavethree1s,soIputathreeinthenumberplacethatcountsones.Eachnumberplaceisnameforthebuildingblockitcounts.Forexample,thisnumberplaceiscallone’splacebecauseitcountsones.

Sohowwegonnawritefractionswiththissystem?Alotoffractionshavethevaluesmallerthan1.Butnowoursmallestbuildingblockis1.Itlookswe’regonnaneedsomesmallerbuildingblocks.

Togetsmallerbuildingblocks,allwehavetodoisstartwith1andkeepdividingby10.

Agoodwaytoseehowthesebuildingblocksworkwiththeotheronesistolookatthenumberline.Ifwedivide1intotenequalparts,theneachofthosepartsisatenth.

Nowournumberlinesshowsthreebuildingblocks,tenoneandtenth.

Andwecangetsmallerbuildingblocksifwekeepdividingby10.Solet’stakeonetenthanddivideitintotenequalparts.Thisevensmallerfractioniscalledahundredth.

Nowthatwehaveallthesesmallerfractionsorbuildingblocks,itmeanswecancountsmallerandsmallerpartsofthings.Buttodothatweneednewnumberplaceforeachofthem.

Toseehowthenewnumberplaceswork,let’sbringbackourlastexampledigits.

Whatweneedisamarkerthatwillhelpustellthemapart,andthatmarkeriscall“decimalpoint”.Thedecimalpointisjustadotthatweputbetweentheones’placeandtenths’place.Sothenumber“253.64”isread“twohundredfiftythreepointsixfour”.That’showyoureadthedecimalpoint,youjustsay“Point”.

Sothedecimalpointisreallyjusttheseparatorbetweenthenumberplacesthatcountwholenumbersfromthenumberplacesthatcountfractions.

Wecallnumbersthatuseadecimalpointdecimalnumberordecimalinshort.

Decimalnumbersordecimalsareimportantbecauseweusethemtoconverthefractionsfromthedivisionproblemintoaregularnumber.

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