用简便方法计算. 4.45+0.63+5.55 5.28-(2.9+1.28) 5.25+7.86-2.86+4.75

1个回答

  • 解题思路:(1)运用加法交换律简算;

    (2)根据减法的性质简算;

    (3)根据加法交换律和结合律简算;

    (4)根据加法结合律和减法的性质简算.

    (1)4.45+0.63+5.55,

    =4.45+5.55+0.63,

    =10+0.63,

    =10.63;

    (2)5.28-(2.9+1.28),

    =5.28-1.28-2.9,

    =4-2.9,

    =1.1;

    (3)5.25+7.86-2.86+4.75,

    =(5.25+4.75)+(7.86-2.86),

    =10+5,

    =15;

    (4)0.96-0.28+0.04-0.72,

    =(0.96+0.04)-(0.28+0.72),

    =1-1,

    =0.

    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: 此题考查小数的加减混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.