2÷[([1/27]-[1/36])×9]×6

3个回答

  • 解题思路:(1)中括号内运用乘法分配律简算,然后再算括号外的除法和乘法;

    (2)根据数字特点,原式变为125×0.67875+125×6.7875+125×0.53375,运用乘法分配律简算.

    (1)2÷[([1/27]-[1/36])×9]×6,

    =2÷[[1/27]×9-[1/36]×9]×6,

    =2÷[[1/3]-[1/4]]×6,

    =2÷[1/12]×6,

    =2×12×6,

    =144;

    (2)1.25×67.875+0.125×6787.5+125×0.53375,

    =125×0.67875+125×6.7875+125×0.53375,

    =125×(0.67875+6.7875+0.53375),

    =125×8,

    =1000.

    点评:

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

    考点点评: 考查了运算定律与简便运算,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律简便计算.