Alright, let's work through 3801 times 1857 step by step
3801 × 1857 = 1857 × (3801)
+ 1857 × 1 that is equal 1857
+ 1857 × 00 giving us 0
+ 1857 × 800 yielding 1485600
+ 1857 × 3000 resulting in 5571000

= 7058457
