Question

计算下面各题，能用简便算法的用简便算法．2.5×4.78×0.4 0.65×101 1.7×2.65+1.35×1.7 7.06

计算下面各题，能用简便算法的用简便算法．2.5×4.78×0.4 0.65×101 1.7×2.65+1.35×1.7 7.06×2.4-5.7 7.28+3.2÷2.5 3.4÷[（1.2+0.5）×5]

Answer 1

（1）2.5×4.78×0.4 
=（2.5×0.4）×4.78
=1×4.78
=4.78

（2）0.65×101 
=0.65×（100+1）
=0.65×100+0.65
=65+0.65
=65.65

（3）1.7×2.65+1.35×1.7
=1.7×（2.65+1.35）
=1.7×4
=6.8

（4）7.06×2.4-5.7
=16.944-5.7
=11.244

（5）7.28+3.2÷2.5
=7.28+1.28
=8.56

（6）3.4÷[（1.2+0.5）×5]
=3.4÷[1.7×5]
=3.4÷1.7÷5
=2÷5
=0.4