Unit6HowdowemeasuretimeExtend（课件）-沪教版英语四年级下册

Unit6Howdowemeasuretime？ExtendTime&HistoryContentsWarm-up&Lead-inStartwithinterestingactivitiestoactivatethinking.AncientTimekeepersExploresundialsandhourglassesinhistory.ModernTimekeepersLearnaboutclocksandwatchesinmodernlife.FunStory&SummaryReadastoryandsummarizekeyknowledgepoints.Warm-up&Lead-inQuestion:Howdowetellthetimenow?Lead-in:Howdidpeopletellthetimeinthepast?Time&History:FromAncientSundialstoModernClocksReading:IntroductionKeepingupwithtimeCanyoutellthetimewithoutaclock?Inthepast,weuseddifferentthingstotellthetime.Question:Whatdifferentthingsdidpeopleusetotellthetimeinthepast?AncientTimekeeper1:Sundial1Thisisasundial.Thesunmakesashadowonthesundial,andtheshadowtellsthetime.Itisoneoftheearliesttimekeepingdevicesusedbyancientpeople.KeyPoint:Sundialsusethepositionofthesuntomeasuretime.Howdoesasundialwork?ThePrincipleofSundialsThesunmakesashadowonthesundial,andtheshadowtellsthetime.Asthesunmovesacrossthesky,theshadow'spositionchanges.Asundialisatime-tellingdevicethatusesthepositionofthesun.Itwasoneoftheearliestwayshumansmeasuredtime.LimitationofaSundialAMajorDrawbackThesundialreliesonsunlighttocastashadow.However:"Butitcannothelpusonacloudyday."KeyTakeaway:Withoutdirectsunlight,thesundialbecomesineffective,highlightingtheneedforalternativetimekeepingmethods.AncientTimekeeper2:Hourglass2Thisisanhourglass.Thesandinitfallsdown.Itcancountdownthetime.AncientTimeMeasurementSeries-Part2Howdoesanhourglasswork?WorkingPrincipleThesandinsidefallsdownthroughanarrowhole.Itcanaccuratelycountdownthetime(e.g.,onehour).KeyFact:Thefallingsandmeasuresthepassageoftime,makingitanancienttimekeepingdevice.ModernTimekeepers:Clock&Watch3.Later,peopleusedclocksandwatchestotellthetime.

Thesedevicesweremoreaccurateandreliablethanancienttoolslikesundialsorhourglasses.Westillrelyonthemtodaytomanageourdailylives.TimeEvolutionModernAccuracyDailyNecessityWestillusethemtoday!Theycomeinmanydifferentstylesanddesigns,buttheyalldothesamejob:tellingthetime.FunStory:IntroductionClassQuestionLookatthepicturecarefully.Thereisaboy,arobot,andabirdonaclock.Whatdoyouthinkthebirdisdoing?Let'sreadthedialoguetofindouttheanswer!FunStory:Dialogue(1)Text:Look!Whyisthebirdsinging?What'sitdoing?Theboyiscuriousaboutthesingingbirdandaskstherobotforananswer."It'stellingthetime.Itsingseveryhour."FunStory:ComprehensionWhyisthebirdsinging?Whatdoesthebirddoeveryhour?DiscusstheanswerswithyourpartnerThink:Whatotherthings?Question:Whatotherthingscanyouusetotellthetime?Hint:Thinkaboutnature,animals,orancienttools...Think:MoreExamplesModernToolsWecanuseourphonesandcomputers.NaturalCluesWecanalsotelltimebythesunriseandsunset.SummaryTimelineofTimekeepers:FromAncienttoModernSundialAncienttimekeepingdeviceusingthesun'sshadow.HourglassAncientmethodtomeasuretimewithflowingsand.Clocks&WatchesModernmechanicaldevicesforprecisetimekeeping.Phones&ComputersDigitaldevicesintegratedwithtimedisplay.Evolution:Fromrelyingonnaturetodigitalprecision.BigQuestionThinkmoreabouttheBigQuestion:Howdowekeepupwithtime?Reflection:Timemanagementisalifelongskill.Considerthetoolsandme