Question

几道五年级数学题

Answer 1

①列竖式计算，你自己打草稿或者按计算器吧，你会用电脑就用电脑里的计算器也行，五年级的题目怎么像一年级的-
-！。
②脱式计算
9.6÷（9.6×4）
=9.6÷9.6÷4
=1÷4
=0.25
0.78÷0.25×4
=0.78×（4÷0.25）
=0.78×16
=12.48
78×0.69+22×6.9
=7.8×6.9+22×6.9
=（7.8+22）×6.9
=（30-0.2）×（7-0.1）
=30×7-30×0.1-0.2×7+0.2×0.1
=210-3-1.4+0.02
=205.62
0.36÷（6.1-4.6）×0.8
=0.36÷1.5×0.8
=0.36÷3×2×0.8
=0.192
4.2×99+4.2
=4.2×（99+1）
=4.2×100
=420
17.8÷（128×4）
=8.9×2÷128÷4
=（8+0.9）÷128÷2
=8÷256+0.9÷256
=0.03125+0.003515625
=0.034765625
146.6-（23+46.5）
=146.6-69.5
=146.6-70+0.5
=77.1

Answer 2

7.9÷0.35=22.571428571429……≈22.6
1.45×0.68=0.986≈1.0
3.12×4.5=14.04≈14.0
（保留一位小数）
7.9÷0.35=22.571428571429……≈22.58
（保留两位小数）
6.76÷2.2=3.0727272727273……≈3.07
三、脱式计算（能简便的要简便）
9.6÷（9.6×4）
=9.6÷9.6÷4
=1÷4
=0.25
0.78÷0.25×4
=3.12×4
=12.48
78×0.69+22×6.9
=7.8×6.9+22×6.9
=6.9×﹙7.8+22﹚
=6.9×29.8
=205.62
0.36÷（6.1-4.6）×0.8
=0.36÷1.5×0.8
=0.24×0.8
=0.192
4.2×99+4.2
=4.2×﹙99+1﹚
=4.2×100
=420
17.8÷（128×4）
=17.8÷512
=0.034765625
146.6-（23+46.5）
=146.6-46.5-23
=100.1-23
=77.1