546-398457+199 2.2×101 5.4×99+5.4 32×0.125×25 .
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解:546-398=148,
457+199=656,
()×21,
=×21,
=9+5+3,
=17;
2.2×101,
=2.2×(100+1),
=2.2×100+2.2×1,
=220+2.2,
=222.2;
5.4×99+5.4,
=5.4×(99+1),
=5.4×100,
=540;
32×0.125×25,
=4×8×0.125×25,
=(4×25)×(0.125×8),
=100×1,
=100;
4.27×+4.73÷8+,
=4.27×+4.73×+,
=×(4.27+4.73+1),
=×10,
=1.25;
(×),
=(4.75×),
=4.75×()×,
=×,
=;
(10.25-5.72-4.28)×,
=[10.25-(5.72+4.28)]×,
=×,
=;
,
=12.75×,
=×(12.75-1.75),
=×11,
=1.
解析分析:灵活运用乘法结合率,加法运算的交换律、结合律来进行计算.
点评:此题考查了运算定律和简便计算.