《2019春一年級(jí)數(shù)學(xué)下冊(cè) 6.2《兩位數(shù)加一位數(shù)和整十?dāng)?shù)》(不進(jìn)位)課件2 (新版)新人教版.ppt》由會(huì)員分享,可在線閱讀,更多相關(guān)《2019春一年級(jí)數(shù)學(xué)下冊(cè) 6.2《兩位數(shù)加一位數(shù)和整十?dāng)?shù)》(不進(jìn)位)課件2 (新版)新人教版.ppt(27頁(yè)珍藏版)》請(qǐng)?jiān)谘b配圖網(wǎng)上搜索。
1、兩位數(shù)加一位數(shù)和整十?dāng)?shù),(不進(jìn)位),30+6= 5+20= 60+4= 9+40=30+60=50+20=60+40= 50+50=,36,25,64,49,90,70,100,100,,一、復(fù)習(xí)舊知:,說(shuō)說(shuō)你是怎樣算的?,填 空,1. 65是由( )個(gè)十和( )個(gè)一組成 的。,2. 29是由( )個(gè)一和( )個(gè)十組成的。,3. 個(gè)位上是7,十位上是4,這個(gè)數(shù)是。,4. 十位上是7,個(gè)位上是4,這個(gè)數(shù)是,,6,5,9,2,47,74,二、探究新知,252?,2520,小林一共要寫 多少個(gè)字?,你能提出什么 數(shù)學(xué)問(wèn)題?,小林和小紅已經(jīng) 寫了多少個(gè)字?,,探究一:,,,,,,,,,,,,353
2、,,,,,,,,,,,,38,探究一,探究二,探究一:,,,,,,,,,,,,353,5個(gè)一加上3個(gè)一是8個(gè)一,3個(gè)十加8個(gè)一是38。,38,探究一,探究二,探究一:,,,,,,,,,,,,426,先把個(gè)位上的數(shù)相加,再和十位上的數(shù)合起來(lái)。,48,試一試。,探究一,探究二,,,,,,,,,,,,,探究二:,3530,65,探究一,探究二,,,,,,,,,,,,,探究二:,3530,,,,,,,,,65,,,,探究一,探究二,,,,,,,,,,,,,探究二:,3530,3個(gè)十加上3個(gè)十是6個(gè)十,6個(gè)十加5個(gè)一是65。,65,探究一,探究二,,,,,,,,,,,,,探究二:,3530,想:3030
3、60 60565,65,探究一,探究二,,,,,,,,,,,,,探究二:,3530,先把十位上的數(shù)相加,再和個(gè)位上的數(shù)合起來(lái)。,65,探究一,探究二,二、探究新知,,(二)兩位數(shù)加一位數(shù)(不進(jìn)位),252,先算527。,,二、探究新知,27,(二)兩位數(shù)加一位數(shù)(不進(jìn)位),252,再算20727。,,二、探究新知,(三)兩位數(shù)加整十?dāng)?shù),2520,先算20加20是40。,,二、探究新知,45,(三)兩位數(shù)加整十?dāng)?shù),2520,再算405是45。,,上面兩題的算法有什么相同和不同的地方?,25 + 2,20,5,7,=27,,,,,25 + 20,20,5,40,= 45,,,,,,,在計(jì)算兩位數(shù)
4、加一位數(shù)時(shí),十位上的數(shù)不變,個(gè)位上的數(shù)相加;計(jì)算兩位數(shù)加整十?dāng)?shù)時(shí),個(gè)位上的數(shù)不變,十位上的數(shù)相加。,對(duì) 比 練 習(xí),35 + 4 =,35 + 40 =,42 + 3 =,5 + 21 =,42 + 30 =,50 + 21 =,,,30,5,,,30,5,,,40,2,,,40,2,,,20,1,,,20,1,,,9,,,5,,,6,,,70,,,70,,,70,45,39,26,75,72,71,,,,,,,20 + 23 =,43(個(gè)),答:一共有43個(gè)學(xué)生。,42+20=,62,5+24=,29,57+2=,59,35+23=,58,41+32=,73,找到答案和我一樣的小動(dòng)物去我家做
5、客!,4+72,76,20+56,46+3,65+1,5+21,53 + 4 = 62 + 7 = 5 + 31 = 86 + 2 = 4 + 72 = 44 + 3 = 20 + 3 = 25 + 3 = 76 + 3 = 2 + 30 =,53 + 20 = 50 + 31 = 72 + 20 = 64 + 30 = 20 + 67 = 45 + 30 = 20 + 30 = 69 + 30 = 32 + 40 = 23 + 60 =,43 + 5 = 32 + 4 = 55 + 1 = 6 + 12 = 40 + 52 = 24 + 30 = 20 + 36 = 25 + 50 = 60 + 13 = 13 + 40 =,口算接力賽,57,69,36,88,76,47,23,28,79,32,48,36,50,99,72,83,53,73,75,56,54,92,18,56,73,81,92,94,87,75,總結(jié),通過(guò)今天的學(xué)習(xí),我們位數(shù)學(xué)會(huì)了兩位數(shù)加一位數(shù)和整十?dāng)?shù)的計(jì)算方法: 計(jì)算兩位數(shù)加一位數(shù)(不進(jìn)位)時(shí),十位上的數(shù)不變,個(gè)位上的數(shù)相加;計(jì)算兩位數(shù)加整十?dāng)?shù)時(shí),個(gè)位上的數(shù)不變,十位上的數(shù)相加。,