请用简便方法计算下面各题245-65-35

1个回答

  • 解题思路:(1)运用减法的性质简算;

    (2)(6)运用加法结合律简算;

    (3)运用乘法结合律简算;

    (4)(5)运用乘法分配律简算.

    (1)245-65-35,

    =245-(65+35),

    =245-100,

    =145;

    (2)186+82+18,

    =186+(82+18),

    =186+100,

    =286;

    (3)25×(4×27),

    =25×4×27,

    =100×27,

    =2700;

    (4)8×(25+20),

    =8×25+8×20,

    =200+160,

    =360;

    (5)24×56+44×24,

    =24×(56+44),

    =24×100,

    =2400;

    (6)5.78+0.32+0.68,

    =5.78+(0.32+0.68),

    =5.78+1,

    =6.78.

    点评:

    本题考点: 运算定律与简便运算;整数四则混合运算.

    考点点评: 完成本题,注意分析式中数据,运用合适的简便方法计算.