125×9642.7-45.27-2.725×201317×17-17×17
125×1613.7+0.98+0.02+4.340-12.85-2.1599×324+324
99×7548.14-2.43-5.57+2.8614×25×3×425.43-(5.43+12.5)

解:(1)125×96,
=125×8×12,
=1000×12,
=12000;

(2)42.7-45.27-2.7,
=(42.7-2.7)-45.27,
=40-45.27,
=-5.27;

(3)25×201,
=25×(200+1),
=25×200+25×1,
=5000+25,
=5025;

(4)317×17-17×17,
=(317-17)×17,
=300×17,
=5100;

(5)125×16,
=125×8×2,
=1000×2,
=2000;

(6)13.7+0.98+0.02+4.3,
=(13.7+4.3)+(0.98+0.02),
=18+1,
=19;

(7)40-12.85-2.15,
=40-(12.85+2.15),
=40-15,
=25;

(8)99×324+324,
=(99+1)×324,
=100×324,
=32400;

(9)99×75,
=(100-1)×75,
=100×75-1×75,
=7500-75,
=7425;

(10)48.14-2.43-5.57+2.86,
=(48.14+2.86)-(2.43+5.57),
=51-8,
=43;

(11)14×25×3×4,
=(14×3)×(25×4),
=42×100,
=4200;

(12)25.43-(5.43+12.5),
=25.43-5.43-12.5,
=20-12.5,
=7.5.
分析:(1)先把96分解成8×12,再運用乘法結(jié)合律簡算;
(2)運用加法交換律簡算;
(3)把201分解成200+1,再運用乘法分配律簡算;
(4)(8)運用乘法分配律簡算;
(5)把16分解成8×2,再運用乘法結(jié)合律簡算;
(6)(10)運用加法結(jié)合律簡算;
(7)(12)根據(jù)連續(xù)減去兩個數(shù)等于減去這兩個數(shù)的和簡算;
(9)把99分解成100-1,再運用乘法分配律簡算;
(11)運用乘法結(jié)合律簡算.
點評:此題是考查四則混合運算,要仔細觀察算式的特點,靈活運用一些定律進行簡便計算.
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