小學(xué)二年級(jí)下冊(cè)數(shù)學(xué)《萬(wàn)以?xún)?nèi)數(shù)的認(rèn)識(shí)》教案

小學(xué)二年級(jí)下冊(cè)數(shù)學(xué)《萬(wàn)以?xún)?nèi)數(shù)的認(rèn)識(shí)》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(biāo)是讓學(xué)生在已經(jīng)掌握100以?xún)?nèi)數(shù)的基礎(chǔ)上，更深入地認(rèn)識(shí)更大的數(shù)。通過(guò)多樣的活動(dòng)和數(shù)形結(jié)合，讓學(xué)生掌握數(shù)數(shù)方法，理解計(jì)數(shù)單位“千”的產(chǎn)生及相鄰計(jì)數(shù)單位間的十進(jìn)關(guān)系。教學(xué)目標(biāo)：1、讓學(xué)生通過(guò)數(shù)數(shù)的過(guò)程，感受大數(shù)的意義。2、認(rèn)識(shí)新的計(jì)數(shù)單位“千”，體會(huì)相鄰兩個(gè)計(jì)數(shù)單位間的十進(jìn)關(guān)系。3、通過(guò)數(shù)一數(shù)、撥一撥和估一估等活動(dòng)，進(jìn)一步培養(yǎng)學(xué)生的數(shù)感。教學(xué)重點(diǎn)：能正確數(shù)出1000以?xún)?nèi)的數(shù)，理解計(jì)數(shù)單位“千”的產(chǎn)生。教學(xué)難點(diǎn)：接近整百、整千拐彎處的數(shù)如何數(shù)。教學(xué)準(zhǔn)備：課件、小棒、紙張和計(jì)數(shù)器等。教學(xué)過(guò)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(qǐng)學(xué)生討論如何數(shù)數(shù)。（一個(gè)一個(gè)地?cái)?shù)）（2）一百個(gè)位置：請(qǐng)學(xué)生討論如何數(shù)數(shù)更方便。（十個(gè)十個(gè)地?cái)?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(lái)學(xué)習(xí)1000以?xún)?nèi)數(shù)的認(rèn)識(shí)。（板書(shū)課題）二、認(rèn)識(shí)計(jì)數(shù)單位“千”1、師生歸納：一千一千地?cái)?shù)，10個(gè)一千是一萬(wàn)。萬(wàn)也是計(jì)數(shù)單位。（板書(shū)）2、在計(jì)數(shù)器上從一千撥到一萬(wàn)。（1）請(qǐng)學(xué)生指出計(jì)數(shù)器上的數(shù)位。（2）學(xué)生以小組為單位撥動(dòng)計(jì)數(shù)器，并思考：當(dāng)撥到九千時(shí)，再增加一千是多少？應(yīng)該怎樣撥珠呢？（3）教師在計(jì)數(shù)器上撥珠，同時(shí)引導(dǎo)學(xué)生邊撥邊數(shù)，使學(xué)生明確：9個(gè)一千再加1個(gè)一千是一萬(wàn)，我們撥到九千后，再撥一千，應(yīng)該把9去掉，并向前一位進(jìn)1。（4）小結(jié)：計(jì)數(shù)單位“千”的前面是“萬(wàn)”，萬(wàn)是更大的計(jì)數(shù)單位。三、整理數(shù)位順序表1、引導(dǎo)學(xué)生回憶學(xué)過(guò)的數(shù)位（個(gè)位、十位、百位、千位、萬(wàn)位）。2、借助計(jì)數(shù)器想一想這些數(shù)位的排列順序（從右往左依次為個(gè)位、十位、百位、千位、萬(wàn)位）。3、組織學(xué)生制作數(shù)位順序表，教師巡視指導(dǎo)。4、展示學(xué)生制作的數(shù)位順序表，并強(qiáng)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(dǎo)學(xué)生在數(shù)位順序表上表示568和302，并讀出這兩個(gè)數(shù)。6、小組討論數(shù)位順序表對(duì)寫(xiě)數(shù)、讀數(shù)有哪些幫助。設(shè)計(jì)意圖：通過(guò)比較不同數(shù)量的物品，讓學(xué)生感知1000的數(shù)量級(jí)，培養(yǎng)學(xué)生的估算能力和比較大小的能力。（一）在演示中感知：1、通過(guò)課件演示，讓學(xué)生數(shù)數(shù)10個(gè)小正方體、100個(gè)小正方體，進(jìn)而感知1000個(gè)小正方體的數(shù)量級(jí)，理解計(jì)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(dòng)中，讓學(xué)生邊操