How to calculate 1.6 × 7.8 × 1.25? And 10.3 × 99 + 10.3

How to calculate 1.6 × 7.8 × 1.25? And 10.3 × 99 + 10.3

1.6×7.8×1.25
=(0.8×2)×7.8×1.25
=(0.8×1.25)×7.8×2
=15.6
10.3×99+10.3
=10.3×(99+1)
=1030