(1)2.5×(6+9.728÷3.2)
=2.5×(6+3.04)
=2.5×9.04
=22.6
(2)45×7.3+27×4.5
=45×(7.3+2.7)
=45×10
=450
(3)0.125×3.2×25
=0.125×8×0.4×25
=(0.125×8)×(0.4×25)
=1×10
=10
(4)[8.3-(3.6+2.9)]÷0.72
=[8.3-6.5]÷0.72
=1.8÷0.72
=2.5
(5)(140+0.42)÷7
=140÷7+0.42÷7
=20+0.06
=20.06
(6)10.2×4.5
=(10+0.2)×4.5
=10×4.5+0.2×4.5
=45+0.9
=45.9