用简便方法计算8.8×0.125 2.5×1.25×32 7.6×5.3+3.7×7.6 37÷0.25÷4 3.85×

1个回答

  • 解题思路:(1)可先将8.8拆分后运用分配律进行简算;

    (2)可将32拆分后运用结合律进行简算;

    (3)、(5)、(6)可据分配律进行简算;

    (4)可据连除相当于除以两个数的积进行简算.

    (1)8.8×0.125

    =(8+0.8)×0.125,

    =8×0.125+0.8×0.125,

    =1+0.1,

    =1.1;

    (2)2.5×1.25×32

    =(2.5×4)×(1.25×8),

    =10×10,

    =100;

    (3)7.6×5.3+3.7×7.6

    =(5.3+3.7)×7.6,

    =9×7.6,

    =68.4;

    (4)37÷0.25÷4

    =37÷(0.25×4),

    =37÷1,

    =37;

    (5)3.85×101-3.85

    =(101-1)×3.85,

    =100×3.85,

    =385;

    (6)(23+4.6)÷2.3

    =23÷2.3+4.6÷2.3,

    =10+2,

    =12.

    点评:

    本题考点: 小数四则混合运算;运算定律与简便运算.

    考点点评: 根据式中数据的特点将式中数据进行拆分简算的方法在四则混合运算中经常用到.