Alright, let's work through 3881 times 1051 step by step
3881 × 1051 = 1051 × (3881)
+ 1051 × 1 yielding 1051
+ 1051 × 80 that results in 84080
+ 1051 × 800 that results in 840800
+ 1051 × 3000 which equals 3153000

= 4078931
