递等式计算.(能巧算的要巧算)380+120÷4    20×(91÷7)120÷5×4625÷5-48     465

1个回答

  • 解题思路:(1)先算除法,再算加法;

    (2)先算小括号里面的除法,再算括号外的乘法;

    (3)按照从左到右的顺序计算;

    (4)先算除法,再算减法;

    (5)运用加法交换律简算;

    (6)先算乘法,再算减法.

    (1)380+120÷4,

    =380+30,

    =410;

    (2)20×(91÷7),

    =20×13,

    =260;

    (3)120÷5×4,

    =24×4,

    =96;

    (4)625÷5-48,

    =125-48,

    =77;

    (5)465+217-165,

    =465-165+217,

    =300+217,

    =517;

    (6)130×8-650,

    =1040-650,

    =390.

    点评:

    本题考点: 整数四则混合运算.

    考点点评: 本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.