Question

脱式计算（能简算的要简算）（1）1.8×2.58+0.5+1.42×1.8（2）（54.7-

脱式计算（能简算的要简算）（1）1.8×2.58+0.5+1.42×1.8（2）（54.7-17.5）×（0.45÷0.9）（3）52.91-311113-18213（4）15-8811+212．

Answer 1

（1）1.8×2.58+0.5+1.42×1.8
=1.8×（2.58+0.5+1.42）
=1.8×4.5
=8.1

（2）（54.7-17.5）×（0.45÷0.9）
=37.2×0.5
=18.6

（3）52.91-31

11

13

-18

2

13

=52.91-（31

11

13

+18

2

13

）
=52.91-50
=2.91

（4）15-8

8

11

+2

1

2

=（15-8+2）-（

8

11

-

1

2

）
=9-

5

22

=8

17

22

Answer 2

(1)1.8×2.58+0.5+1.42×1.8
=1.8×(2.58+1.42)+0.5
=1.8×4+0.5
=7.2+0.5
=7.7;
(2)(54.7-17.5)×(0.45÷0.9)
=37.2×0.5
=18.6;
(3)1.5×(0.1÷0.2)-0.18÷0.36
=1.5×0.5-0.5
=0.75-0.5
=0.25;
(4)93.6÷[(54.8+45.2)×(6-5.46)]
=93.6÷[100×0.54]
=93.6÷54
=1.7
•
3
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