分数乘法的简单运用Simple application offraction multiplication.docx

分数乘法的简单运用Simple application offraction multiplication.docx

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分数乘法的简单运用Simpleapplicationoffractionmultiplication

4分数乘法的简单运用（Simpleapplicationof4fractionmultiplication）

Simpleapplicationof11.fractionmultiplication

Brieftips

Jiangsuprimaryschoolmathematicstextbooksonthesixthgrade,forty-firstcasesofpage3and"try","practice",practiceeightitem12-17,"alittlebitofanumberofafewsimplepracticalproblems".

Stilltodoforexamplechouhuamaterial,combinedwiththespecificsituation,guidethestudentstousethefractionalmultiplicationlearnedtosolvepracticalproblemsrelatedtotheunderstandingoftherichnumberfraction,laythefoundationforfurtherstudytoanswerpracticalproblemsregardingthescoresslightlycomplex.Intheprocessofsolvingproblems,studentsfurthercultivatetheabilityofobservation,comparison,analysisandreasoning,andexperiencethefunofmathematicslearning.

Teachingprocess

Process1:

newknowledgeintoa

Process2:

newknowledgeintob

Process3:

teachingcase3A

Process4:

teachingcase3B

Process5:

teachingcase3C

Process6:

trya

Process7:

tryB

Process8:

tryC

Process9:

practiceandpracticea

Process10:

practiceandpracticeB

Process11:

"exerciseeight"Twelfthquestionsa

Process12:

"exerciseeight"TwelfthquestionsB

Process13:

"exerciseeight"thirteenthquestionsa

Process14:

"exerciseeight"thirteenthquestionsB

Process15:

exerciseeight,item14-16,a

Process16:

exerciseeight,item14-16,B

Process17:

"exerciseeight"seventeenthquestionsa

Process18:

"exerciseeight"seventeenthquestionsB

Process19:

afullcoursesummary

Paragraph1:

teachingexamples3and"try""

Teacher:

thesixthgradestudentstodothethreecolorsofsilkflowerforNationalDayeveningpartyofvariouskindsofflowers,flowernumbershown,pleasesee!

Process1:

newknowledgeintoa

（look）3casesofthesixthgradestudentstodothethreecolorsofsilkflowerforNationalDayeveningpartyofvariouskindsofflowers,flowernumbershown.

Teacher:

pleaselookatthepicturecarefully.Canyouusethescoretodescribetherelationshipbetweenvariousquantitiesinthegraph?

Groupclassmatessaysomethingtoeachother.

Process2:

newknowledgeintob

1.Iftheyellowflowernumber"1"asaunit,safflowerisyellow,greenflowerisyellow（）;ifyouputtheredflowersasthenumberofunitsof"1",yellowisredflowers,greenflowersarered;

Ifthegreenflowernumber"1"asaunit,safflowerisgreenflowers,yellowgreenflowers（is）

Process3:

teachingcase3A

1（look）flowerhas50morethantheyellowflower,safflower,saffloweryellowthanhowmanyroses?

Pleaselookatthepicture:

whatpartofthepictureisthenumberofflowersofsafflowermorethanthatofyellowflowers?

Whoistheresultofcomparingitwiththat?

Whatkindofflowersisit?

（courseware）howmanyflowersarethereinsafflowerthaninyellowflowers?

Process4:

teachingcase3B

Theredthantheyellow,redandyellowflowersarerelativelyfewflowernumberresults.Thenumberofyellowflowersasaunit"1",safflowerismorethanthenumberofyellowflowers,thatis,50flowers.

（courseware）toaskformoresafflowerthanyellowflowers,thatis,askfor50flowers.

Canyoucalculatethisprobleminarow?

Writeitonyourexercisebook.

Process5:

teachingcase3C

1（look）50x=5（a）a:

5morethantheyellowflowerofsafflower.

Whosays,"whatdoyouthinkwhenyoumakealist?

""Safflowermorethanyellowflowers",isthenumberofflowersasaunit"1",safflowermorethanthenumberofyellowflowersis50,thatis,for50flowers.

Process6:

trya

（courseware）greenflowerslessthanyellowflowers,greenflowerslessthanthenumberofflowers

Thinkaboutthenumberof"greenflowersarelessthanthoseofyellowflowers."whichnumbershouldbeconsideredas"unit1"?

Ask"greenflowerlessthantheflowerofyellowflower",thatis,howmanyflowers?

Pleasecountthemindependently.

Process7:

tryB

Pleaseseethe"try"toanswerthisquestion.（coursewareshow）50x=20（Duo）

Answer:

greenflowerslessthan20flowers.

Greenflowerslessthantheyellowflowers,hereisthenumberofgreenflowersandthenumberofyellowflowerscomparedtothenumberofflowersasaunitof"1",seekinggreenflowerslessthanthenumberofflowers,istoaskthe50ishowmuch.

Process8:

tryC

Reflection:

whatdoyouthinkisthekeytounderstandingthequantitativerelationshipexpressedbyfractions?

Itispointedoutthatthekeytounderstandingthequantityrelationexpressedbyfractionistoknowwhichfractionistheresultofthecomparisonofthetwoquantities.Whencomparing,thequantityisregardedasunit1.

Thesecondparagraph:

"practiceandpractice""

Teacher:

thestudentsareaskedtoanswerthe2questionsof"practiceandpractice"independently!

Process9:

practiceandpracticea

（coursewareshow）.

Thelittlearmyhas28stamps,andthesmalleronesaremorethanthesmallones.Howmuchisthesmallforcesmallerthanthesmallarmy?

Askthestudentstodoitindependently.Thinkaboutthescoreofeachquestion,whichistheresultofthecomparisonofthetwoquantities,whichnumberisregardedastheunit"1"incomparison?

Whatquantitydoestheunit"1"mean?

Process10:

practiceandpracticeB

Pleaseanswerthetwoquestionsof"practiceandpractice".（Courseware:

onebyone）

Thedeltadeltadelta200020002000

Thenumber,thenumberofmorethan5,lessthan10.

Morethan2000Delta

（2）-A（6）,lessthana.

Teacher:

lookatthe"practice"thefirstquestionleft,delta6,thenumberofhoursismorethana,6,6（a）,x=2,2morethanthe.Look,right,8,anumberoflessthan10%,isless8,8x=6（a）,lessthan6hours.

Thelittlearmyhas28stamps,andthesmalleronesaremorethanthesmallones.Howmuchisthesmallforcesmallerthanthesmallarmy?

28x=8（Zhang）answer:

smallforcethansmallarmymorethan8.

Teacher:

theconditionof"smallforceofstampsismorethansmallarmy",thatis,smallforcethansmallarmynumberissmallarmystampnumber,thatis,28,souse28x=8（Zhang）.

Thirdparagraph:

exerciseseighttotwelfthto17questions

Teacher:

let'sthinkaboutsomeexercisesofeight,please!

Process11:

"exerciseeight"Twelfthquestionsa

（look）,calculatethefollowingquestions,thenobservedthesubjectandresults,whathaveyoufound?

Studentsareaskedtoobservethesizeofeachsetofscores.Aftercalculating,compareeachintegralwithfactor15（or36）.Communicateyourfindingsingroupsbycomparison.

Process12:

"exerciseeight"TwelfthquestionsB

Lookatthecalculationsonthescreen,checkitout.（coursewareshow）

324

15x=9x36=45

2581

Throughobservationandcomparison,itcanbefoundthat

（1）thenumberofthecoursewareismultipliedbythefractiongreaterthanthe1,andtheresultislargerthantheoriginalnumber;anumberismultipliedbythefractionsmallerthan1,andtheresultissmallerthantheoriginalnumber.

Process13:

"exerciseeight"thirteenthquestionsa

（coursewareshow）

Askthestudentstoobservecharacteristicsofeachmultiplicationformula,withtwelfthquestionsfoundinlaw,directlydeterminedwithtwochannelformuladatasize.Directjudgment,youcanalsobeverifiedbyfurthercalculation.

Process14:

"exerciseeight"thirteenthquestionsB

Lookattheresultsofeachofthealgorithmspresentedonthescreen.（coursewareshow）

X16<16x13<<13

X15>14x36x=x36

Whosaid,thetwoquestionsinfrontofyou,whatdoyouthink?

Process15:

exerciseeight,item14-16,a

Nowpleasecarefullyandanswerthefollowingquestionsindependently.（coursewareshow）

Wefirsttalkaboutthescoresofallthesignificanceoftherelationshipbetweenthenumberofcompletetype.

Theballthenumberoffootballmorethan.

Thenumberof（x）=x（）

Theactualwaterconsumptionthanplannedsavings.

Waterconsumption（x=（））

Thereare24classesinthenewprimaryschoolcanlastyear,thisyeartoexpandthescale,increasethenumberofclassesthanlastyear.Howmanyclasseshavebeenaddedthisyear?

asweater,price56yuan,nowthepricelowerthantheoriginal.Howmuchisthepricereduction?

Process16:

exerciseeight,item14-16,B

Let'slookattheanswerstothesequestionstogether.（Courseware:

onebyone）

Wefirsttalkaboutthescoresofallthesignificanceoftherelationshipbetweenthenumberofcompletetype.

Theballthenumberoffootballmorethan.

Thenumberof（football）=（ballismorethanfootball）

[teacher:

thenumberofballsismorethanfootball,andthenumberoffootballisregardedastheunit"1"

Theactualwaterconsumptionthanplannedsavings.

（planned）waterconsumptionx=（actualsaving）waterconsumption

[Division:

theactualwaterconsumptionislessthantheoriginalplan,theoriginalplannedwaterconsumptionasunit"1"]

Thereare24classesinthenewprimaryschoolcanlastyear,thisyeartoexpandthescale,increasethenumberofclassesthanlastyear.Howmanyclasseshavebeenaddedthisyear?

24x9（a）answer:

9classeshavebeenaddedthisyear.

[teacher:

"thisyearthanlastyear,"istheresultofthisyear'sclassnumbercomparedwithlastyear,thenumberofclasseslastyearasaunit"1","thisyearincreasedthenumberofclasses",istoask"24ishowmuch"

asweater,price56yuan,nowthepricelowerthantheoriginal.Howmuchisthepricereduction?

56x=16（yuan）answer:

16yuanreduction.

[teacher:

thequestionof"howmuchisthepricereduction"istheresultofcomparingthepresentpricewiththeoriginalprice.Theoriginalpriceisregardedastheunit"1",andthe"howmuchisthepricereduction"istoask"howmuchis56yuan"?

Groupstudentscombinethespeci