(2012•安溪县)用你喜欢的方法计算下面各题

1个回答

  • 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.