解题思路:(1)运用减法的性质简算;
(2)运用除法的性质简算;
(3)先算除法和乘法,再算加法;
(4)把32看做8×4,运用乘法交换律与结合律简算;
(5)把百分数和分数化为小数,运用乘法分配律简算;
(6)先算括号内的,再算括号外的.
(1)8.85-0.25-0.75,
=8.85-(0.25+0.75),
=8.85-1,
=7.85;
(2)(51+[34/27])÷17,
=51÷17+[34/27]÷17,
=3+[34/27]×[1/17],
=3+[2/27],
=3[2/27];
(3)375+450÷18×25,
=375+25×25,
=375+625,
=1000;
(4)1.25×0.25×32,
=1.25×0.25×4×8,
=1.25×8×(0.25×4),
=10×1,
=10;
(5)14.2×25%+[4/5]×[1/4],
=14.2×0.25+0.8×0.25,
=(14.2+0.8)×0.25,
=15×0.25,
=3.75;
(6)[1/4]÷(1-[1/2]-[1/4]),
=[1/4]÷[1/4],
=1.
点评:
本题考点: 运算定律与简便运算;整数四则混合运算;分数除法;分数的简便计算;分数的四则混合运算.
考点点评: 此题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.