Question

计算下面各题．6.45-2.74+3.6 &nb...

计算下面各题．6.45-2.74+3.6 45.36+（83.4-15.07）4.5+3.8+15.567.39-（12.67+17.39）35.62-8.38-5.62 2.06+5.42+3.94+2.58．

Answer 1

（1）6.45-2.74+3.6
=3.71+3.6
=7.31；

（2）45.36+（83.4-15.07）
=45.36+68.33
=113.69；

（3）4.5+3.8+15.5
=（4.5+15.5）+3.8
=20+3.8
=23.8；

（4）67.39-（12.67+17.39）
=67.39-12.67-17.39
=（67.39-17.39）-12.67
=50-12.67
=37.33；

（5）35.62-8.38-5.62           
=35.62-5.62-8.38       
=30-8.38
=21.62；

（6）2.06+5.42+3.94+2.58
=（2.06+3.94）+（2.58+5.42）
=6+8
=14．