Question

4．已知兩個(gè)因數(shù)的積是6.384，其中一個(gè)因數(shù)是5.7，另一個(gè)因數(shù)是兩位小數(shù)．

Answer 1

分析 因?yàn)榉e的小數(shù)點(diǎn)位數(shù)是每個(gè)因數(shù)的小數(shù)點(diǎn)位數(shù)之和，所以求一個(gè)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(gè)因數(shù)的小數(shù)點(diǎn)位數(shù)是1，
所以另一個(gè)因數(shù)的小數(shù)點(diǎn)位數(shù)是：3-1=2，
答：另一個(gè)因數(shù)有兩位小數(shù)．
故答案為：兩．

點(diǎn)評(píng) 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(gè)因數(shù)的小數(shù)點(diǎn)位數(shù)之和．