Question

已知兩個因數(shù)的積是12.684，其中一個因數(shù)是3.1，另一個因數(shù)有

 

位小數(shù)．

Answer 1

考點(diǎn)：小數(shù)除法,乘與除的互逆關(guān)系

專題：文字?jǐn)⑹鲱}

分析：因?yàn)榉e的小數(shù)點(diǎn)位數(shù)是每個因數(shù)的小數(shù)點(diǎn)位數(shù)之和，所以求一個因數(shù)的小數(shù)點(diǎn)位數(shù)用積的小數(shù)點(diǎn)位數(shù)減去另一因數(shù)的小數(shù)點(diǎn)位數(shù)即可．

解答： 解：積的小數(shù)點(diǎn)位數(shù)是3，一個因數(shù)的小數(shù)點(diǎn)位數(shù)是1，所以另一個因數(shù)的小數(shù)點(diǎn)位數(shù)是：
3-1=2，
所以另一個因數(shù)有兩位小數(shù)．
故答案為：兩．

點(diǎn)評：本題考查了小數(shù)乘法中積的小數(shù)點(diǎn)的位數(shù)與各因數(shù)小數(shù)點(diǎn)的位數(shù)之間的關(guān)系．積的小數(shù)點(diǎn)位數(shù)是每個因數(shù)的小數(shù)點(diǎn)位數(shù)之和．