(1)3.72×3.5+62.8×0.35                      
(2)9.9×8.6+0.86
(3)15.02-6.8-1.02-3.2                   
(4)725÷0.125÷0.25÷32
(5)8888888×77777777÷1111111÷2222222-9999999÷3333333.
分析:(1)把62.8×0.35化成6.28×3.5,再運(yùn)用乘法分配律簡算;
(2)把0.86化成8.6×0.1,再運(yùn)用乘法分配律簡算;
(3)根據(jù)減法的性質(zhì)進(jìn)行簡算;
(4)根據(jù)除法的性質(zhì)進(jìn)行簡算;
(5)根據(jù)整數(shù)運(yùn)算定律進(jìn)行簡算.
解答:解:(1)3.72×3.5+62.8×0.35,
=3.72×3.5+6.28×3.5,
=(3.72+6.28)×3.5,
=10×3.5,
=35;

(2)9.9×8.6+8.6×0.1,
=8.6×(9.9+0.1),
=8.6×10,
=86;

(3)15.02-6.8-1.02-3.2,
=(15.02-1.02)-(6.8+3.2 ),
=14-10,
=4;

(4)725÷0.125÷0.25÷32,
=725÷[(0.125×8)×(0.25×4)],
=725÷[1×1],
=725÷1,
=725;

(5)8888888×77777777÷1111111÷2222222-9999999÷3333333,
=8×7×1111111×1111111÷1111111÷1111111÷2-1111111×9÷1111111÷3,
=8×7÷2-9÷3,
=28-3,
=25.
點評:本題考查了運(yùn)算定律與簡便運(yùn)算,四則混合運(yùn)算,注意運(yùn)算順序和運(yùn)算法則,靈活運(yùn)用所學(xué)的運(yùn)算律簡便計算.
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