递等式计算,写出必要的计算过程,能简便计算的用简便方法计算:

1个回答

  • 解题思路:(1)、(5)、(6)、(7)、(8)按照有括号的先算括号里面的,没有括号时先算乘除法,后算加减法的顺序计算;

    (2)、(3)运用乘法分配律进行简算得解;

    (4)运用乘法结合律简算得解.

    (1)7.06×2.4-5.7,

    =16.944-5.7,

    =11.244;

    (2)5.4×99+5.4,

    =5.4×(99+1),

    =5.4×100,

    =540;

    (3)9.6×72+9.6×28,

    =9.6×(72+28),

    =9.6×100,

    =960;

    (4)(1.25×2.5)×4,

    =1.25×(2.5×4),

    =1.25×10,

    =12.5;

    (5)10.4+72×0.81,

    =10.4+58.32,

    =68.72;

    (6)11×0.6×0.4,

    =6.6×0.4,

    =2.64;

    (7)(12.8+4.99)÷0.2,

    =17.79÷0.2,

    =88.95;

    (8)1.25×8+2.5×4.4,

    =10+2.5×0.4×11,

    =10+11,

    =21.

    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: 此题考查小数四则混合运算与简便计算,完成本题要注意分析式中数据,运用合适的简便方法计算.