简便计算.(1)169+226+274(2)(923+174)+26(3)(75×25)×4(4)2×34×50(5)3

1个回答

  • 解题思路:(1)(2)根据加法的结合律计算即可;

    (3)根据乘法的结合律计算即可;

    (4)(6)(8)根据乘法的交换律和结合律计算即可;

    (5)根据加法的交换律和结合律计算即可;

    (7)根据加法的交换律和结合律以及连减的简算计算即可;

    (10)先凑整再计算即可.

    (1)169+226+274,

    =169+(226+274),

    =169+500,

    =669;

    (2)(923+174)+26,

    =923+(174+26),

    =923+200,

    =1123;

    (3)(75×25)×4,

    =75×(25×4),

    =75×100,

    =7500;

    (4)2×34×50,

    =2×50×34,

    =100×34,

    =3400;

    (5)357+432+368+153,

    =(357+153)+(432+368),

    =510+800,

    =1310;

    (6)13×125×7×8,

    =(13×7)×(125×8),

    =91×1000,

    =91000;

    (7)385-173+615-227,

    =(385+615)-(173+227),

    =1000-400,

    =600;

    (8)16×(125×6),

    =(8×2)×(125×6),

    =(8×125)×(2×6),

    =1000×12,

    =12000;

    (9)9+98+997+9996+99995+999994+21,

    =(9+1)+(98+2)+(997+3)+(9996+4)+(99995+5)+(999994+6),

    =10+100+1000+10000+100000+1000000,

    =1111110.

    点评:

    本题考点: 四则混合运算中的巧算;整数四则混合运算.

    考点点评: 考查了四则混合运算中的巧算,解题的关键是灵活运用运算律简便计算.