Alright, let's work through 3870 times 8163 step by step
3870 × 8163 = 8163 × (3870)
+ 8163 × 0 resulting in 0
+ 8163 × 70 what gives us 571410
+ 8163 × 800 yielding 6530400
+ 8163 × 3000 what gives us 24489000

= 31590810
