用自己喜欢的方法计算5-21417-131771×990.625×0.5+[5/8]+[1/2]×62.5%8.37-3

1个回答

  • 解题思路:(1)5-

    2

    14

    17

    -

    1

    3

    17

    ,应用减法的运算性质进行简算;

    (2)71×99,转化为71×(100-1),应用乘法分配律进行简算;

    (3)0.625×0.5+[5/8]+[1/2]×62.5%,把[5/8]和62.5%都化成小数,再应用乘法分配律进行简算;

    (4)8.37-3.25-(1.37+1.75),应用减法的运算性质进行简算;

    (5)45×([7/9]+[4/15]-0.6),应用乘法分配律进行简算;

    (6)0.25×48转化为0.25×4×12,应用乘法结合律进行简算.

    (1)5-2

    14

    17-1

    3

    17,

    =5-(2[14/17+

    3

    17]),

    =5-3,

    =2;

    (2)71×99,

    =71×(100-1),

    =71×100-71,

    =7100-71,

    =7029;

    (3)0.625×0.5+[5/8]+[1/2]×62.5%,

    =0.625×0.5+0.625+0.5×0.625,

    =0.625×(0.5+0.5+1),

    =0.625×2,

    =1.25;

    (4)8.37-3.25-(1.37+1.75),

    =8.37-1.37-(3.25+1.75),

    =7-5,

    =2;

    (5)45×([7/9]+[4/15]-0.6),

    =45×[7/9]+45×[4/15]-45×0.6,

    =35+12-27,

    =20;

    (6)0.25×48,

    =(0.25×4)×12,

    =1×12,

    =12.

    点评:

    本题考点: 运算定律与简便运算;整数、分数、小数、百分数四则混合运算.

    考点点评: 此题考查的目的是灵活运用运算定律、运算性质对整数、小数、分数四则混合运算进行简便计算.