脱式计算(能简算的要简算):62.8×19-8×6245-62453.64×[1÷(2110-2.09)]1800-1350÷18×6(2512+158+2712+3.375)×3201.9-1.9×(1.9-1.9)(1-1%×70)÷27.-数学
题文
脱式计算(能简算的要简算):
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答案
(1)62.8×19-8×62
=62.8×(19-8-1), =62.8×10, =628; (2)3.64×[1÷(2
=3.64×[1÷0.01], =3.64×100, =364; (3)1800-1350÷18×6, =1800-75×6, =1800-450, =1350; (4)(2
=(5+5)×
=
(5)1.9-1.9×(1.9-1.9), =1.9-0, =1.9; (6)(1-1%×70)÷
=(1-
= |