36被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法

1、人教版 數(shù)學(xué) 五年級(jí) 上冊(cè)被除數(shù)的小數(shù)位數(shù)比被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法除數(shù)少的除法復(fù)習(xí)復(fù)習(xí)導(dǎo)導(dǎo)入入探究新知探究新知課堂小結(jié)課堂小結(jié)課后作業(yè)課后作業(yè)小數(shù)除法小數(shù)除法課堂練習(xí)課堂練習(xí)3 3被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回復(fù)習(xí)復(fù)習(xí)導(dǎo)導(dǎo)入入移動(dòng)除數(shù)小數(shù)點(diǎn)，移動(dòng)除數(shù)小數(shù)點(diǎn)，使它變?yōu)檎麛?shù)；使它變?yōu)檎麛?shù)；除數(shù)的小數(shù)點(diǎn)向除數(shù)的小數(shù)點(diǎn)向右移動(dòng)幾位，被右移動(dòng)幾位，被除數(shù)的小數(shù)點(diǎn)也除數(shù)的小數(shù)點(diǎn)也向右移動(dòng)幾位；向右移動(dòng)幾位；按除數(shù)是整數(shù)的按除數(shù)是整數(shù)的小數(shù)除法計(jì)算。小數(shù)除法計(jì)算。一個(gè)數(shù)除以小數(shù)的計(jì)算方法一個(gè)數(shù)除以小數(shù)的計(jì)算方法被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回被除數(shù)小數(shù)位被除數(shù)小數(shù)位數(shù)數(shù)不夠怎么辦？不夠怎么辦？

2、3.783.782.82.8 2828把下面的算式轉(zhuǎn)化成除數(shù)是整數(shù)的除法算式把下面的算式轉(zhuǎn)化成除數(shù)是整數(shù)的除法算式12.612.60.280.28 282837.837.8？被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回探究新知探究新知12.6 12.6 0.28 0.28 0.280.2812.612.6. . .在被除數(shù)的末在被除數(shù)的末尾用尾用“0 0”補(bǔ)足。補(bǔ)足。0 04 411 211 2 1 41 4 0 05 51 4 01 4 0 0 04545被除數(shù)位數(shù)不被除數(shù)位數(shù)不夠怎么辦？夠怎么辦？例題例題5 5被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回大家來討論：計(jì)算除數(shù)是大家來討論：計(jì)算除數(shù)是小數(shù)的除法是

3、怎樣計(jì)算的？小數(shù)的除法是怎樣計(jì)算的？先移動(dòng)除數(shù)的小數(shù)先移動(dòng)除數(shù)的小數(shù)點(diǎn)，使它變成點(diǎn)，使它變成整數(shù)。整數(shù)。除數(shù)的小數(shù)點(diǎn)向右移除數(shù)的小數(shù)點(diǎn)向右移動(dòng)幾位，動(dòng)幾位，被除數(shù)被除數(shù)的小的小數(shù)點(diǎn)也向右移動(dòng)幾位。數(shù)點(diǎn)也向右移動(dòng)幾位。位數(shù)不夠的，在被位數(shù)不夠的，在被除數(shù)的末尾用除數(shù)的末尾用0 0補(bǔ)足。補(bǔ)足。然后按除數(shù)是整數(shù)的然后按除數(shù)是整數(shù)的小數(shù)除法進(jìn)行計(jì)算。小數(shù)除法進(jìn)行計(jì)算。被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回1.1.列列豎式計(jì)算。豎式計(jì)算。2.192.190.3 5.580.3 5.583.1 0.843.1 0.843.53.5課堂練習(xí)課堂練習(xí)2.1 92.1 90.30.37 72 12 19 93 39

4、 90 05.5 85.5 83.13.13 13 11 12 42 40.8 40.8 43.53.50 07 07 01 41 42 21 4 01 4 00 0 0 0. . .=7.3=7.3=1.8=1.8=0.24=0.24. .8 8. .8 82 4 82 4 80 0 4 4 0 0被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回2.2.下面下面的計(jì)算對(duì)嗎？如果不對(duì)，錯(cuò)在哪里？的計(jì)算對(duì)嗎？如果不對(duì)，錯(cuò)在哪里？（ ）改正：改正：1.4 41.4 41.81.81 4 41 4 48 80 01.4 41.4 41.81.81 4 41 4 4. .0 00 0. .8 8被除數(shù)的小數(shù)位數(shù)比除

5、數(shù)少的除法返回2.2.下面下面的計(jì)算對(duì)嗎？如果不對(duì)，錯(cuò)在哪里？的計(jì)算對(duì)嗎？如果不對(duì)，錯(cuò)在哪里？（ ）改正：改正：11.711.72.62.610 410 44 41 3 01 3 01 3 01 3 00 05 511.711.72.62.610 410 4.0.00 04 4. .5 51 31 31 3 01 3 00 0被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回3.3.填空填空。（1 1）兩個(gè)數(shù)相除，除數(shù)擴(kuò)大到原來的）兩個(gè)數(shù)相除，除數(shù)擴(kuò)大到原來的10001000倍，要倍，要使商不變，被除數(shù)應(yīng)（使商不變，被除數(shù)應(yīng)（ ）。）。（2 2）計(jì)算）計(jì)算0.320.320.80.8時(shí)應(yīng)先化成時(shí)應(yīng)先化成( )

6、( )( )( )，再計(jì)算。再計(jì)算。8 8 擴(kuò)大到原來的擴(kuò)大到原來的10001000倍倍3.23.2被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回4.4.把把下面的算式變成除數(shù)是整數(shù)的除法算式。下面的算式變成除數(shù)是整數(shù)的除法算式。0.560.560.25=( )0.25=( )25253.883.880.32=( )0.32=( )( )( )1 10.18=( )0.18=( )18185.35.30.326=( )0.326=( )( )( )3883885656323210010032632653005300被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回5.5.根據(jù)根據(jù)87587535=2535=25直接寫出下

7、列各式的商。直接寫出下列各式的商。8.758.750.35=( )0.35=( )0.0250.02525258758753.5=( )3.5=( )0.8750.87535=( )35=( )0.8750.8750.35=( )0.35=( )2502502.52.5被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回34.834.81.6 34.81.6 34.834.834.80.16 34.80.16 34.834.834.81 34.81 34.86.6.在在里填上里填上“” “” “” “=” “=”。 = =你發(fā)現(xiàn)規(guī)律了嗎？你發(fā)現(xiàn)規(guī)律了嗎？被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回當(dāng)除數(shù)當(dāng)除數(shù)1 1時(shí)，被

8、除數(shù)商；時(shí)，被除數(shù)商；當(dāng)除數(shù)當(dāng)除數(shù)1 1時(shí)，被除數(shù)商；時(shí)，被除數(shù)商；當(dāng)除數(shù)當(dāng)除數(shù)=1=1時(shí)，被除數(shù)時(shí)，被除數(shù)= =商。商。34.834.81.6 34.81.6 34.834.834.80.16 34.80.16 34.834.834.81 34.81 34.86.6.在在里填上里填上“” “” “” “=” “=”。 = =被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回7.7.水果水果店新進(jìn)一批橘子店新進(jìn)一批橘子, ,平均每箱可賺平均每箱可賺12.512.5元元, ,一共賺了一共賺了500500元。水果店賣出了多少箱橘子元。水果店賣出了多少箱橘子? ?5 0 05 0 012.512.54 45 0 0

9、5 0 00 0 40 40（箱）（箱）0 0 50050012.512.5答：水果店賣出了答：水果店賣出了4040箱橘子。箱橘子。0 0被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回1 1個(gè)普通的白熾燈年個(gè)普通的白熾燈年耗電量約為耗電量約為71.571.5度。度。換成節(jié)能燈，一年換成節(jié)能燈，一年可省可省55.2555.25度電。度電。白熾燈的年耗電量是節(jié)能燈的多少倍？白熾燈的年耗電量是節(jié)能燈的多少倍？節(jié)能燈的年耗電量：節(jié)能燈的年耗電量：71.571.555.2555.258.8.被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回71.571.5節(jié)能燈的年耗電量：節(jié)能燈的年耗電量： 71.571.555.25=16.25(55.25=16.25(度度) )71.571.516.25=16.25=16.2516.2565 0 065 0 00 00 04 4. .4 46 56 56 5 0 06 5 0 00 00 04.44.4答：白熾燈的年耗電量是答：白熾燈的年耗電量是節(jié)能燈的節(jié)能燈的4.44.4倍。倍。被除數(shù)的小數(shù)位數(shù)比除數(shù)少的除法返回這節(jié)課你們都學(xué)會(huì)了哪些知識(shí)？這節(jié)課你們都學(xué)會(huì)了哪些知識(shí)？計(jì)算被除數(shù)的小數(shù)位數(shù)比除數(shù)少的小數(shù)計(jì)算被除數(shù)的小數(shù)位數(shù)比除數(shù)少的小數(shù)除法時(shí)除法時(shí), ,將除數(shù)和