(1)79.76+84.7×0.2 (2)15.37+28.44+12.56 (3)(2.3×8.8-2.3×0.8)×

1个回答

  • 解题思路:(1)先算乘法,再算加法;

    (2)根据加法结合律进行计算;

    (3)根据乘法分配律进行计算;

    (4)先算除法,再算加法,再算减法,最后算乘法.

    (1)79.76+84.7×0.2,

    =79.76+16.94,

    =96.7;

    (2)15.37+28.44+12.56,

    =15.37+(28.44+12.56),

    =15.37+41,

    =56.37;

    (3)(2.3×8.8-2.3×0.8)×1.25,

    =2.3×(8.8-0.8)×1.25,

    =2.3×8×1.25,

    =2.3×(8×1.25),

    =2.3×10,

    =23;

    (4)[5.2-(2.5+7.5÷5)]×1.2,

    =[5.2-(2.5+1.5)]×1.2,

    =[5.2-4]×1.2,

    =1.2×1.2,

    =1.44.

    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: 四则运算,先弄清运算顺序,然后再进一步计算,能简算的要简算.