(1)27-3.6-6.4
=27-(3.6+6.4)
=27-10
=17;
(2)125.125×8
=(125+0.125)×8
=125×8+0.125×8
=1000+1
=1001;
(3)3.2×0.125
=(0.4×8)×0.125
=0.4×(8×0.125)
=0.4×1
=0.4;
(4)0.5×20.1+15.05
=10.05+15.05
=25.1;
(5)40.3+25.6-10.7
=65.9-10.7
=55.2;
(6)9.9+1.2-9.9+1.5
=(9.9-9.9)+(1.2+1.5)
=0+2.7
=2.7.