解
6.25×7×8
=6.25×4×2×7
=25×2×7
=350
2.05×6.53-2.05×0.33
=2.05×（6.53-0.33）
=2.05×6.2
=2.05×（6+0.2）
=2.05×6+2.05×0.2
=12.3+0.41
=12.71