最新人教版小学四年级下数学小数点的移动课件PPT.ppt 53页

'人教版小学四年级下数学小数点的移动 例5小数点移动的规律 小数点移动与的长短有什么关系？小数点往右移，金箍棒越变越大! 填空：1、把2.3的小数点向右移动一位,原数就（）了（）倍2、把0.375扩大100倍，小数点向（）移动（）位。3、把0.73的小数点向（）移动（）位，原数缩小100倍。4、把30的小数点向（）移动（）位，原数变成0.03。扩大10右2左2左3 0.01平方米把0.01平方米扩大到它的10倍、100倍、1000倍，各是多少？0.1平方米例6小数点右移扩大 0.01×10=0.10.1×10=1数的扩大一个数扩大10倍，小数点向右移动一位；一个数扩大100倍，小数点向右移动两位；一个数扩大1000倍，小数点向右移动三位；‥‥‥把0.01扩大10倍就是把它乘以10。 1平方米0.1平方米把1平方米缩小到它的、、…，各是多少？101100011001例7小数点左移缩小 1÷10=0.10.1÷10=0.01数的缩小‥‥‥一个数数缩小1000倍，小数点向左移动三位；一个数缩小100倍，小数点向左移动两位；一个数缩小10倍，小数点向左移动一位；把1平方米缩小为原来的，就是把它除以10。101 在下表的空格里填上正确的数.原数的10倍原数的100倍原数的1000倍1.0750.0363.540.410.750.3635.44107.53.6354401075363540400练习 下面的数去掉小数点,各是原数的多少倍?0.70.250.080.4053.617258405361(10倍)(100倍)(100倍)(1000倍)(100倍)练习 智力擂台 1919019002.360.2360.0236 710251006100050610002410 0.3681000.541100.7295100.12861000 3扩大1000左3缩小100078右 35.28扩大十倍选择正确的答案。3.528352.80.352835280.035283528035.28缩小十倍35.28缩小一千倍35.28扩大一百倍 126126大家好，我是小数点，别看我个子小，本领却大极了，只要我动一动，要那些数变大就大，变小就小。 谢谢大家! 小数点移动练习课 小数点向右移动一位，小数就扩大到原数的（）倍；小数点向右移动两位，小数就扩大到原数的（）倍；小数点向右移动三位，小数就扩大到原数的（）倍；101001000小数点向左移动一位，小数就缩小到原数的（）倍；小数点向左移动一位，小数就缩小到原数的（）倍；小数点向左移动一位，小数就缩小到原数的（）倍；101100110001 扩大10倍缩小10倍扩大100倍缩小100倍8、 26.3元263元2630元4.5元45元450元38.9元389元3890元 小数的末尾添上“0”或去掉“0”，小数的大小不变。为什么？ 43.9＞43.6＞38.5＞37.8小强＞小军＞小芳＞小红 0.360.0314100010001 122324567071 2.342.433.243.424.234.3223.424.332.434.242.343.2 谢谢大家 新视野大学英语读写教程第三版B2U1SectionA课后练习答案 Pre-readingactivitiesP2Ex.11MichalstartedlearningEnglishbylisteningtotheBeatles.2MichalfeelsdelightedandproudwhenhelistenstotheBeatlesbecausehecanunderstandalotbetter.3BesideslisteningtoEnglishsongs,MichalalsoreadssciencefictionbooksinEnglish.4MichalmadeagreatbreakthroughinlearningtheEnglishlanguageaftersuccessfullyfinishingreadingthefirstEnglishbook.5AccordingtoMichal,Englishlearningbringshimsatisfactionandpleasure. Pre-readingactivitiesP2Ex.21•Yes,becausethewaytolearnEnglishismoreinterestingandenjoyable.•Yes,becauselearnersbecomemoremotivatedwhenlearningsomethingtheylike.•No,becauseit’slikeastreetlearningwithoutformalinstruction.2•Yes,Icouldspeakandwritemorefluentlywithgoodgrammarandvocabulary.•Yes,IcouldbetterunderstandEnglishnativespeakersafterwatchingEnglishmoviesandtalkshows.•Yes,asaresultofsurfingonlineinEnglish,I’mabletoreadmorequicklythanbefore. Pre-readingactivitiesP23•ReadEnglishnovelsandmagazines.•ListentoradiosandwatchTVprograms.•TalktoEnglishspeakerswheneverpossible.•Writeeverydaysuchasemailsandjournals. Pre-readingactivitiesP2Script:I"mMichal.IliveinPoland,andPolishismynativelanguage.IstartedlearningEnglishbylisteningtotheBeatleseveryday.Atthebeginning,Ididn’tknowwhattheyweresinging,butsoonIstartedtounderstandindividualwords,andlater,more.EachtimeIhearaBeatlessong,IamdelightedandfeelproudbecausenowIcanunderstandalotbetter.Ilistentomanyrockbands,allinEnglish,andIreallyenjoythem.BesideslisteningtoEnglishsongs,IalsostartedreadingsciencefictionbooksinEnglish.IstillrememberhowexcitedIwaswhenIsuccessfullyfinishedreadingthefirstEnglishbook,agreatbreakthroughinmylife!WhenIreadinEnglish,Inotonlyhavethepleasureofreadingbutalsogetthefeelingofself-accomplishment.Englishhasgivenmesomuchsatisfactionandpleasure.IfeelI’mfree. Understandingthetext（P9）1、Becauseheistiredoflisteningtohisfatherandheisnotinterestedingrammarrules.2、ThecivilizationofGreeceandthegloryofRomanarchitecturearesomarvelousandremarkablethattheyshouldbedescribedatleastinabriefaccount;however,whatthestudentcoulddowasonlyonesingleutterance:“whoa!”withoutanyanyspecificcomment.3、Becausetheschoolsfailtosethighstandardsoflanguageproficiency.Theyonlyteachalittlegrammarandlessadvancedvocabulary.Andtheyoungerteachersthemselveshavelittleknowledgeofthevitalstructuresoflanguage.4、Becauseteachinggrammarisnotaneasyjobandmostofthestudentswilleasilygetboredifit’snotproperlydealtwith. 5、Hefamiliarizedhissonwithdifferentpartsofspeechinasentenceanddiscussedtheirspecificgrammaticalfunctionsincludinghowtouseadverbstodescribeverbs.6、BecausethesonhadneverheardaboutthevariousnamesandfunctionsofwordsinanEnglishsentencebefore.7、Theauthoruses“roadmap"and“car"todescribegrammarandvocabulary.Here,"roadmap"isconsideredasgrammarand“car"asvocabulary.8、Sincethesubjunctivemoodhissonusedisafairlyadvancedgrammarstructure,theinterjection“whoa!”reflectsthetremendouspridethefatherhadtowardhisson;italsoreflectstheauthor’shumorinusingthewordbecauseitwasonceusedbyhisstudent,thoughintwodifferentsituationsandwithtwodifferentfeelings. CriticalthinkingP91•Motivation.•Familysupport.•Peerpressure.•Financialstatus.•Futurecareergoals.2•Englishgrammarhelpsalotinthefollowing:•Ordersentencescorrectly.•Usewordsproperly.•TalkwithotherEnglishspeakersconfidently.Englishgrammarisoflittlehelp:•Onlygivesrulesthatarehardtoremember.•Isnothelpfulinareal-lifesettingduetothelimitedtimetothinkandrecalltherules.•Notalwaysapplicabletothereallanguage,especiallyidioms. CriticalthinkingP93•Usemorecommunicativeways.•Encouragealotofinteractions.•Putsentencesinmeaningfulcontexts.4•ReadmoreEnglishfromonlinesources.•WatchEnglishTV/listentoEnglishradio/watchEnglishonlinevideos.•TalkoftenwithEnglishspeakers.•Listencarefullyandextensively.•Usedictionariestolookupunfamiliarwords.•Usenewwordsasoftenaspossible.5•ReadEnglishnewspapers,magazines,andbooks.•WriteEnglishasoftenaspossible.•WriteemailsinEnglish. Ex.3Wordsinuse（P9）1.condense2.exceed3.deficit4.exposure5.asset6.adequate7.competent8.adjusting9.precisely10.beneficial WordbuildingP11Ex.4WordslearnedNewwordsformed-al/-ialmanagermanagerialeditoreditorialsubstantialsubstancesurvivesurvivaltraditionaltraditionmarginalmargin-cyconsistentconsistencyaccurateaccuracyefficiencyefficient-yrecoverrecoveryministerministryassembleassembly WordbuildingP11Ex.51editorial2recovery3accuracy4substance5managerial6margin7assembly8Ministry9survival10tradition11consistency12efficient BankedclozeP1261L2C3J4A5I6O7N8E9H10F ExpressionsinuseP121feelobligedto2beseriousabout3runinto4distinguishbetween5thrustupon6wasallergicto7getlost8beattractedto9makesense10lookeduponas StructuredwritingP15Somebookwormsinmydormitoryoftenspendhoursreadingtheir“Bible”,PracticalEnglishGrammar,anddoalotofexercisesinthatbook,butIdon’tcareaboutitatall.MyassumptionissinceIhaveneverlearnedChinesegrammar,what’sthesenseoflearningEnglishgrammar？Infact,Englishgrammarhasalwaysbeenabigheadachetome. Englishgrammarisverycomplicatedbecause,unlikeChinese,therearemanyverbtenses.Evenstrangerthanverbtenses,Englishgrammaralsocontainssomethingveryconfusing.Forexample,Idon’trememberhowmanytimesmymiddleschoolteachertriedto“impose”thedifferencesbetweenusedtoandbeusedtoonus.Sometimeshewouldgoonwiththeexplanationfor20minutesorso.Heevensummarizedthedifferencesbylistingthreeorfourpointsforustomemorize.However,theycouldneverstayinmyhead.Idon’trememberhowmanytimesIgotitwrongwiththesentencescontainingusedtoorbeusedtoonmyexams.Iwasreallyconfusedwiththesetwophrases,andIcannevergetthemright. Inbrief,I’mallergictolearningEnglishgrammar.Curiously,IjustwonderifthenativespeakersofEnglishhaveamicrocomputerintheirbraintohelpthemutterthetwophrasespromptlywithjustaclickoftheirbrainmouse! TranslationP16Englishisknownasaworldlanguage,regularlyusedbymanynationswhoseEnglishisnottheirfirstlanguage.人们普遍认为英语是一种世界语言，经常被许多不以英语为第一语言的国家使用。Likeotherlanguages,Englishhaschangedgreatly.与其他语言一样，英语也发生了很大的变化。ThehistoryoftheEnglishlanguagecanbedividedintothreemainperiods:OldEnglish,MiddleEnglishandModernEnglish.英语的历史可以分为三个主要阶段：古英语，中古英语和现代英语。 TranslationP16TheEnglishlanguagestartedwiththeinvasionofBritainbythreeGermanictribesduringthe5thcenturyAD,andtheycontributedgreatlytotheformationoftheEnglishlanguage.英语起源于公元5世纪，当时三个日耳曼部落入侵英国，他们对英语语言的形成起了很大的作用。Duringthemedievalandearlymodernperiods,theinfluenceofEnglishspreadthroughouttheBritishIsles,andfromtheearly17thcenturyitsinfluencebegantobefeltthroughouttheworld.在中世纪和现代社会初期，英语的影响遍及不列颠群岛。从17世纪初，它的影响力开始在世界各地显现。 TranslationP16TheprocessesofEuropeanexplorationandcolonizationforseveralcenturiesledtosignificantchangeinEnglish.欧洲几百年的探险和殖民过程导致了英语的重大变化。Today,AmericanEnglishisparticularlyinfluential,duetothepopularityofAmericancinema,television,music,tradeandtechnology,includingtheInternet.今天，由于美国电影、电视、音乐、贸易和技术、包括互联网的大受欢迎，美国英语的影响力尤其显著。 TranslationP16中国书法（calligraphy）是一门独特的艺术，是世界上独一无二的艺术瑰宝。中国书法艺术的形成、发展与汉文字的产生与演进存在着密不可分的关系。汉字在漫长的演变发展过程中，一方面起着交流思想、继承文化的重要作用，另一方面它本身又形成了一种独特的艺术。Chinesecalligraphyisauniqueartandtheuniquearttreasureintheworld..TheformationanddevelopmentoftheChinesecalligraphyiscloselyrelatedtotheemergenceandevolutionofChinesecharacters.Inthislongevolutionaryprocess,Chinesecharactershavenotonlyplayedanimportantroleinexchangingideasandtransmittingculturebutalsodevelopedintoauniqueartform. TranslationP16书法能够通过作品把书法家个人的生活感受、学识、修养、个性等折射出来，所以，通常有“字如其人”的说法。中国书法不仅是中华民族的文化瑰宝，而且在世界文化艺术宝库中独放异彩。Calligraphicworkswellreflectcalligraphers’personalfeelings,knowledge,self-cultivation,personality,andsoforth,thusthereisanexpressionthat“seeingthecalligrapher’shandwritingislikeseeingtheperson”.AsoneofthetreasuresofChineseculture,Chinesecalligraphyshinessplendidlyintheworld’streasurehouseofcultureandart。.'