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.