解题思路:(1)根据加法结合律简便计算;
(2)根据减法的性质计算;
(3)将47.23+72.29-27.23变形为47.23-27.23+72.29进行计算.
(1)5.8+2.47+7.53
=5.8+(2.47+7.53)
=5.8+10
=15.8;
(2)81.52-60.25-0.75
=81.52-(60.25+0.75)
=81.52-61
=20.52;
(3)47.23+72.29-27.23
=47.23-27.23+72.29
=20+72.29
=92.29.
点评:
本题考点: 运算定律与简便运算.
考点点评: 考查了运算定律与简便运算,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简便计算.