Question

列豎式計(jì)算 3.08×0.45=

*9.88÷1.9=

△3.92÷3.7=．

Answer 1

分析：（1）計(jì)算時(shí)末位對(duì)齊，按照整數(shù)乘法的方法計(jì)算，看因數(shù)中有幾位小數(shù)，就在積里從末位數(shù)幾位并點(diǎn)上小數(shù)點(diǎn)．
（2）把除數(shù)擴(kuò)大10倍，被除數(shù)就變?yōu)?8.8，按照整數(shù)除法法則進(jìn)行相除，商的小數(shù)點(diǎn)和被除數(shù)的小數(shù)點(diǎn)對(duì)齊．
（3）當(dāng)不能除盡時(shí)，除到小數(shù)點(diǎn)后第三位，結(jié)果保留兩位小數(shù)．

解答：解：3.08×0.45=1.386  

（2）9.88÷1.9=5.2 

（3）3.92÷3.7≈1.06

點(diǎn)評(píng)：掌握小數(shù)乘除法法則是解決本題的關(guān)鍵，乘時(shí)末位對(duì)齊，除時(shí)商的小數(shù)點(diǎn)和被除數(shù)的小數(shù)點(diǎn)對(duì)齊．