小學二年級下冊數(shù)學《萬以內(nèi)數(shù)的認識》教案

小學二年級下冊數(shù)學《萬以內(nèi)數(shù)的認識》教案Inthethirdstageofnumberrecognition,studentsinsecondgradelearnaboutnumberswithintenthousand.However,sincetheirabilitytounderstandabstractconceptsisnotfullyformed,thebasicprincipleremainsthedecimalsystem.Basedonthestudents'understandingofthefourdigits"ones,tens,hundreds,thousands,"thislessonallowsstudentstofullyexperiencetheprocessofcountingandunderstandtheformationofabstractnumbers.Byunderstandingandmasteringtheconceptthat"10thousandsmakeonemillion,"studentsdeepentheirunderstandingofthedecimalsystemanddeveloptheirsenseofnumbers.1.Combiningnumbersandshapes,stepbystep,deepeningunderstanding.Thislessonstartswithacontextualimage,allowingstudentstofeeltheapplicationofnumbersindailylife.Then,usingsquarewoodenblocksandcountersasmaterials,studentscountuptoonethousand,furtherunderstandingtheprinciplesofdecimalcountingandtheconceptthat"10thousandsmakeonemillion."Finally,studentsareguidedtoorganizeandcreateatableofnumbersequences,inspiringtheirinterestinlearningwhilefurtherunderstandingthemeaningandfunctionofdigits,andexploringthepracticalvalueofnumbersequencetables.2.Fromintuitivetoabstract,deepeningunderstandingofconcepts.Thislessonfocusesonallowingstudentstoexperiencetheprocessofcounting,usingactivitiessuchascountingstarstodeepentheirunderstandingofcountingunitsandmethods.Throughgraduallyabstractingsquarewoodenblocksandcounters,studentscanintuitivelyfeeltheprocessofformingconcepts,andgraduallydeveloptheirsenseofnumbers.Lessonpreparation:TeacherpreparesPPTcourseware,counters,andatableofnumbersequences.Studentspreparecounters.Teachingprocess:Contextualintroduction,inspiringinterest1.Displaythecoursewareandappreciate"largenumbers."(1)Introduction:Thereismathematicalknowledgeeverywhereinourlives.Look,thisisourcampus.Pleasereadthesenumbersinourcampus.(2)Studentstrytoreadthenumbers.(3)GuidestudentstoviewthepictureoftheNanjingYangtzeRiverBridgeandreadthenumbers:thelengthofthehighwaybridgeis4,589meters,andthelengthoftherailwaybridgeis6,772meters.2.Revealthetopic.Teacher:Itseemsthattherearemanynumberslargerthanthousandsinourlives.Today,wewilllearnaboutthem.(Writethetopicontheboard:Understandingnumberswithintenthousand)Designintention:Bycreatingacontext,studentsareguidedtopayattentiontomathematicalphenomenaindailylife,generatetheneedtorecognizenumberswithintenthousand,experiencetheconnectionbetweenmathematicsandlife,anddevelopstudents'patrioticemotions.Discovernewknowledgeandguidediscovery(1)Reviewcountingmethods.(1)Studentsworkingroupsanddiscuss:Whatcountingunitshaveyoulearned?Whatistheincrementbetweenadjacentcountingunits?(2)Studentsreportonthecountingmethodstheyhavelearned.(2)Guidestudentstocountsquarewoodenblocks.(1)GuidestudentstoobservethesquarewoodenblocksinExample5andcountthem.(2)Studentsexchangeideasoncountingmethods.(Countbytenstoreachonehundred,thencountbyonehundredtoreachonethousand,whichisexactlyonelargesquarewoodenblock.Thencountonethousandbyonethousand,andtenthousandsmakeonemillion.)本課的目標是讓學生在已經(jīng)掌握100以內(nèi)數(shù)的基礎(chǔ)上，更深入地認識更大的數(shù)。通過多樣的活動和數(shù)形結(jié)合，讓學生掌握數(shù)數(shù)方法，理解計數(shù)單位“千”的產(chǎn)生及相鄰計數(shù)單位間的十進關(guān)系。教學目標：1、讓學生通過數(shù)數(shù)的過程，感受大數(shù)的意義。2、認識新的計數(shù)單位“千”，體會相鄰兩個計數(shù)單位間的十進關(guān)系。3、通過數(shù)一數(shù)、撥一撥和估一估等活動，進一步培養(yǎng)學生的數(shù)感。教學重點：能正確數(shù)出1000以內(nèi)的數(shù)，理解計數(shù)單位“千”的產(chǎn)生。教學難點：接近整百、整千拐彎處的數(shù)如何數(shù)。教學準備：課件、小棒、紙張和計數(shù)器等。教學過程：一、創(chuàng)設(shè)情境，激趣揭題（一）課件演示：體育館情境圖1、猜一猜：體育館大約能容納多少人。2、數(shù)一數(shù)：（1）一排位置：請學生討論如何數(shù)數(shù)。（一個一個地數(shù)）（2）一百個位置：請學生討論如何數(shù)數(shù)更方便。（十個十個地數(shù)）（二）揭示課題：比一百更大的數(shù)怎么數(shù)呢？今天，我們一起來學習1000以內(nèi)數(shù)的認識。（板書課題）二、認識計數(shù)單位“千”1、師生歸納：一千一千地數(shù)，10個一千是一萬。萬也是計數(shù)單位。（板書）2、在計數(shù)器上從一千撥到一萬。（1）請學生指出計數(shù)器上的數(shù)位。（2）學生以小組為單位撥動計數(shù)器，并思考：當撥到九千時，再增加一千是多少？應(yīng)該怎樣撥珠呢？（3）教師在計數(shù)器上撥珠，同時引導學生邊撥邊數(shù)，使學生明確：9個一千再加1個一千是一萬，我們撥到九千后，再撥一千，應(yīng)該把9去掉，并向前一位進1。（4）小結(jié)：計數(shù)單位“千”的前面是“萬”，萬是更大的計數(shù)單位。三、整理數(shù)位順序表1、引導學生回憶學過的數(shù)位（個位、十位、百位、千位、萬位）。2、借助計數(shù)器想一想這些數(shù)位的排列順序（從右往左依次為個位、十位、百位、千位、萬位）。3、組織學生制作數(shù)位順序表，教師巡視指導。4、展示學生制作的數(shù)位順序表，并強調(diào)數(shù)位順序表要從右往左，從低位到高位依次排列。5、指導學生在數(shù)位順序表上表示568和302，并讀出這兩個數(shù)。6、小組討論數(shù)位順序表對寫數(shù)、讀數(shù)有哪些幫助。設(shè)計意圖：通過比較不同數(shù)量的物品，讓學生感知1000的數(shù)量級，培養(yǎng)學生的估算能力和比較大小的能力。（一）在演示中感知：1、通過課件演示，讓學生數(shù)數(shù)10個小正方體、100個小正方體，進而感知1000個小正方體的數(shù)量級，理解計數(shù)單位“千”的產(chǎn)生和意義。2、在分組合作數(shù)小棒、同桌合作撥珠子的活動中，讓學生邊操