问题
解答题
怎样简便怎样计算:
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答案
(1)31.2×91+3.12×90,
=31.2×91+31.2×9,
=31.2×(91+9),
=31.2×100,
=3120;
(2)0.25×3.2×12.5,
=0.25×8×0.4×12.5,
=(0.25×0.4)×(8×12.5),
=0.1×100,
=10;
(3)2.95×101-2.95,
=2.95×(101-1),
=2.95×100,
=295;
(4)89×100.1,
=89×(100+0.1),
=89×100+89×0.1,
=8900+8.9,
=8908.9;
(5)99÷0.25÷0.4,
=99÷(0.25×0.4),
=99÷0.1,
=990;
(6)35.6-6×1.73,
=35.6-10.38,
=25.22.