9.6×0.04的積有________位小數(shù)
0.96÷0.4=________÷4.
三 9.6
分析:(1)9.6與0.04的末尾數(shù)9×4=36,末尾沒有0,所以9.6×0.04的積的小數(shù)位數(shù)等于9.6與0.04的小數(shù)位數(shù)和;
(2)0.96÷0.4,被除數(shù)和除數(shù)同時擴大10倍,它們的商不變.
解答:
(1)9.6是一位小數(shù);0.04是兩位小數(shù);
6×4=24;1+2=3;
所以,9.6×0.04的積有三位小數(shù);
(2)0.96÷0.4,
=(0.96×10)÷(0.4×10),
=9.6÷4,
=2.4.
故答案為:三,9.6.
點評:兩個小數(shù)相乘,這兩個小數(shù)的末尾數(shù)相乘的積的末尾沒有0,那么這兩個小數(shù)的乘積的小數(shù)位數(shù)是這兩個數(shù)的小數(shù)位數(shù)和;
被除數(shù)和除數(shù)擴大(縮。┫嗤谋稊(shù)(0除外),商不變.