scalingnumbers-mathspool-homepage缩放数字数学池-主页

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1、PupilresourcesheetParallelnumberlines:examplesPupilresourcesheetParallelnumberlinesMR1Y8MRScalingNumbersa→b5→84→52→516→52→34→36.4→22.4x?MR3Y8MRabab710.50.81.21½2¼24361.42.1MR3Y8MRProportionalsetsornot?Identifywhichsetsofnumbersareinproportion.Thenforthosecompletethetablesbelow.Example1Example2Exam

2、ple3Example4abababaB511.25826.25749123.60.30.67528.25242.50.75715.75311.253.512.2572.1122740122.2520400601824545.518.7586492.7ExampleScalefactorInversescalefactorExampleScalefactorInversescalefactorratioratioinverseasdivisorfractionxxinverseasdivisorfractionxx¸decimalxx¸decimalxxpercentagexxpercen

3、tagexxExampleScalefactorInversescalefactorExampleScalefactorInversescalefactorratioratioinverseasdivisorfractionxxinverseasdivisorfractionxx¸decimalxx¸decimalxxpercentagexxpercentagexxMR3Y8MRExampleScalefactorInversescalefactorratioinverseasdivisorfractionxx¸decimalxxpercentagexxMR3Y8MRMR4Y8MRRati

4、oandProportionab357x91510.517.5a3y910.5b5201517.5RatioandProportionMR4Y8MRFindthemissingnumbers.Showallyourworkingout.Example1Example2abab9137213.519.538.5112028.89y1015x5616Example3a2810864b7727.5z176Examplea12t19.2144b517860BetweencolumnsabMR4Y8MR456.8?Withincolumnsab456.8?PupilresourcesheetMR4Y

5、8MRMultiplicativerelationships:keyresultsFractions,decimalsandpercentagesWhenusingacalculator,itiseasiesttodealwithnumbersexpressedindecimalform.Toconvertafractiontoadecimal:a/b=a÷b.Example:5/8=5÷8=0.625Toconvertapercentagetoadecimal,orviceversa,rememberthatpercentagesarehundredths:Examples:89%=0.

6、89,2.75=275%×?ScalefactorsToscaleatob,multiplybyb/a.Toscalebtoa,multiplybya/b.×?Example:5445scalefactor=0.8scalefactor=1.255×0.8=44×1.25=5ProportionsTwopairsofnumbersareinproportionifthescalefactorsforthepairsofnumbersareequal.Example:ab541083528b/a=4/5=8/10=28/35=0.8Biggerorsmaller?Whensolvingpro

7、blemsinvolvingmultiplicationanddivisionitisusefultoaskyourself‘Willtheanswerbesmallerorwillitbebigger?’Startingwithanypositivenumbern:¨Multiplyingnbyanumberbiggerthan1increasesn.Example:0.25×5=1.25(biggerthan0.25