豎式計算:
①0.65×1.14
②10.3÷42 (保留兩位小數(shù))
③3.64÷15 (商用循環(huán)小數(shù)表示)
解:①0.65×1.14=0.741,
1.14
,
②10.3÷42≈0.25(保留兩位小數(shù)),
0.245
③3.64÷15=0.242
(商用循環(huán)小數(shù)表示),
0.2426
,
故答案為:0.741;0.25;0.242
.
分析:(1)按這整數(shù)乘法的方法進(jìn)行計算,再看因數(shù)中一共有幾位小數(shù),就從積的末尾起數(shù)出幾位點上小數(shù)點.
(2)按整數(shù)除法的計算方法進(jìn)行計算.
點評:此題考查小數(shù)乘法,小數(shù)除法,小數(shù)乘法按整數(shù)乘法法則計算;小數(shù)除法,按照整數(shù)除法計算,要注意商的小數(shù)點要和被除數(shù)的小數(shù)點對齊.