3.5 一個數(shù)除以小數(shù)（2）【知識精講精研】五年級數(shù)學(xué)上冊人教版

一個數(shù)除以小數(shù)（2）第三單元小數(shù)除法第五課時1.列豎式計(jì)算。81.9÷920.5÷0.581.99981.9190=9.120.50.54205150=4101復(fù)習(xí)導(dǎo)入一個數(shù)除以小數(shù)的計(jì)算方法01復(fù)習(xí)導(dǎo)入一看：看清除數(shù)有幾位小數(shù)；二移：把除數(shù)和被除數(shù)的小數(shù)點(diǎn)同時向右移動相同的位數(shù)，使除數(shù)變成整數(shù)，當(dāng)被除數(shù)位數(shù)不夠時，添0補(bǔ)足；三算：按照除數(shù)是整數(shù)的除法計(jì)算。0在被除數(shù)的末尾用“0”補(bǔ)足。12.6÷0.28＝________0.2812.6被除數(shù)位數(shù)不夠怎么辦？02探究新知00.2812.64504112140014502探究新知12.6÷0.28＝________你會計(jì)算了嗎？先移動除數(shù)的小數(shù)點(diǎn)，使它變成整數(shù)。除數(shù)的小數(shù)點(diǎn)向右移動幾位，被除數(shù)的小數(shù)點(diǎn)也向右移動幾位。位數(shù)不夠的，在被除數(shù)的末尾用0補(bǔ)足。然后按除數(shù)是整數(shù)的小數(shù)除法進(jìn)行計(jì)算。除數(shù)是小數(shù)的除法是怎樣計(jì)算的？02探究新知大家來討論：除數(shù)是小數(shù)的除法應(yīng)該怎樣計(jì)算？1.先移動除數(shù)的小數(shù)點(diǎn)，使它變成

；2.除數(shù)的小數(shù)點(diǎn)向右移動幾位，

的小數(shù)點(diǎn)也向右移

動幾位（位數(shù)不夠的，在被除數(shù)的末尾用

補(bǔ)足）；3.然后按除數(shù)是整數(shù)的小數(shù)除法進(jìn)行計(jì)算。整數(shù)被除數(shù)002探究新知1.計(jì)算下面各題。2192.19÷0.3=7.35.58÷3.1=1.830..9921073..55831..24824831018..03課堂練習(xí)0.84÷3.5=0.248435..14

14070002..0407057.05÷0.47=15470..2352354701503課堂練習(xí)1.計(jì)算下面各題。0051.3÷0.27=19025.6÷0.032=80051327..2432432701925632.256080.00000003課堂練習(xí)1.計(jì)算下面各題。26÷0.13=2002613.260200005885.88÷0.56=10.5560..28280560105.00被除數(shù)位數(shù)不夠，要用0來補(bǔ)足。03課堂練習(xí)1.計(jì)算下面各題。2.下面各題算得對嗎？把不對的改正過來。1441.8.14408.1441.8.144008.除數(shù)的小數(shù)點(diǎn)向右移動一位，被除數(shù)的小數(shù)點(diǎn)也要向右移動一位。訂正：×03課堂練習(xí)11.726.13013010404513130.11.726.1040450×4.4.832.12812832014.√訂正：03課堂練習(xí)2.下面各題算得對嗎？把不對的改正過來。被除數(shù)273273027.30.273除數(shù)131.30.130.013商2121211302.7321213.根據(jù)第一列里的數(shù)填出其他各列里的數(shù)。03課堂練習(xí)4.算一算。03課堂練習(xí)180181.8242.40.24300.30.03÷

=

÷

=

13.5

7.5

7.5

7.5

0.45

45

450

5.把下面的算式變成除數(shù)是整數(shù)的除法算式。0.56÷0.25=(

)÷253.88÷0.32=(

)÷(

)1÷0.18=(

)÷185.3÷0.326=(

)÷(

)3885632100326530003課堂練習(xí)04課堂小結(jié)這節(jié)課有什么收獲呢？除數(shù)是小數(shù)的除法計(jì)算方法1.移動除數(shù)的小數(shù)點(diǎn),使它變成整數(shù)；2.除數(shù)的小數(shù)點(diǎn)向右移動幾位,被除數(shù)的小數(shù)點(diǎn)也向右