解题思路:(1)首先把0.72分成0.8×0.9,然后根据乘法结合律简算即可;
(2)根据加法交换律和加法结合律简算即可;
(3)根据乘法分配律简算即可;
(4)根据乘法分配律简算即可;
(5)根据乘法分配律简算即可;
(6)根据乘法分配律简算即可.
(1)1.25×0.72
=1.25×0.8×0.9
=0.9
(2)50.27+5.6-10.27
=50.27-10.27+5.6
=40+5.6
=45.6
(3)5.65×9.9+0.565
=5.65×9.9+5.65×0.1
=5.65×(9.9+0.1)
=5.65×10
=56.5
(4)(0.4+40)×2.5
=0.4×2.5+40×2.5
=1+100
=101
(5)10.1×101-10.1
=10.1×(101-1)
=10.1×100
=1010
(6)9.7×0.72-0.7×0.72+0.72
=0.72×(9.7-0.7+1)
=0.72×10
=7.2
点评:
本题考点: 运算定律与简便运算;小数四则混合运算.
考点点评: 此题主要考查了加法、乘法运算定律在简算中的应用.