问题 解答题
脱式计算,能简便的要简便计算.
42÷(5.25÷0.25)

0.4+12.6÷0.28×0.2
8.4-8.4×1.5÷1.80.27×99+0.27
2.5×3.2×0.12513.5÷2.5÷0.125÷0.4÷8.
答案

①42÷(5.25÷0.25)

=42÷(5.25×4)

=42÷21

=2

②0.4+12.6÷0.28×0.2

=0.4+45×0.2

=0.4+9

=9.4

③8.4-8.4×1.5÷1.8

=8.4×(1-

5
6

=8.4×

1
6

=1.4

④0.27×99+0.27

=0.27×(99+1)

=0.27×100

=27

⑤2.5×3.2×0.125

=2.5×(0.4×8)×0.125

=(2.5×0.4)×(8×0.125)

=1×1

=1

⑥13.5÷2.5÷0.125÷0.4÷8

=13.5÷(2.5×0.125×0.4×8)

=13.5÷[(2.5×0.4)×(0.125×8)]

=13.5÷[1×1]

=13.5÷1

=13.5.

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