Question

列豎式計(jì)算．
①55.08÷8.5=
②7.8×8.15=
③3.425÷0.24=（得數(shù)保留兩位小數(shù)）

Answer 1

分析：①先把除數(shù)的小數(shù)點(diǎn)向右移動(dòng)一位，使它變成整數(shù)，除數(shù)的小數(shù)點(diǎn)向右移動(dòng)幾位，被除數(shù)的小數(shù)點(diǎn)也向右移動(dòng)相同的位數(shù)，然后按著除數(shù)是整數(shù)方法進(jìn)行計(jì)算．
②按整數(shù)乘法的方法進(jìn)行計(jì)算，再看因數(shù)中一共有幾位小數(shù)，就從積的末尾起數(shù)出幾位點(diǎn)上小數(shù)點(diǎn)．
③先把除數(shù)的小數(shù)點(diǎn)向右移動(dòng)二位，使它變成整數(shù)，除數(shù)的小數(shù)點(diǎn)向右移動(dòng)幾位，被除數(shù)的小數(shù)點(diǎn)也向右移動(dòng)相同的位數(shù)，然后按著除數(shù)是整數(shù)方法進(jìn)行計(jì)算，再將得數(shù)保留兩位小數(shù)．

解答：解：①55.08÷8.5=6.48；


②7.8×8.15=63.57；
       8.1 5
×7.8
      

.

65 2 0

    57 0 5
   

.

63.5 7 0

③3.425÷0.24≈14.27．

點(diǎn)評(píng)：此題考查小數(shù)乘法，小數(shù)除法，小數(shù)乘法按整數(shù)乘法法則計(jì)算；小數(shù)除法，先移動(dòng)除數(shù)的小數(shù)點(diǎn)使它變成整數(shù)，然后按除數(shù)是整數(shù)除法計(jì)算．