①3.25×5.69+3.25×3.31+3.25

=3.25×（5.69+3.31+1）

=3.25×10

=32.5；

②12.5×32×2.5

=（12.5×8）×（4×2.5）

=100×10

=1000；

③（200-1456÷26）×24

=（200-56）×24

=144×24

=3456；

④5.4÷（3.94+0.86）×0.8

=5.4÷4.8×0.8

=1.125×0.8

=0.9．