Alright, let's work through 3893 times 1037 step by step
3893 × 1037 = 1037 × (3893)
+ 1037 × 3 yielding 3111
+ 1037 × 90 what gives us 93330
+ 1037 × 800 which equals 829600
+ 1037 × 3000 giving us 3111000

= 4037041
