(1)1.08×0.8÷0.9,
=0.864÷0.9,
=0.96;
(2)3.4×5.3+6.6×5.3,
=(3.4+6.6)×5.3,
=10×5.3,
=53;
(3)0.25×12.5×0.8×4,
=(0.25×4)×(12.5×0.8),
=1×10,
=10;
(4)7.28+3.2÷2.5,
=7.28+1.28,
=8.56;
(5)1.8×102,
=1.8×(100+2),
=1.8×100+1.8×2,
=180+3.6,
=183.6;
(6)44.28÷0.9÷4.1,
=49.2÷4.1,
=12.