Alright, let's work through 3891 times 517 step by step
3891 × 517 = 517 × (3891)
+ 517 × 1 that is equal 517
+ 517 × 90 giving us 46530
+ 517 × 800 what gives us 413600
+ 517 × 3000 what gives us 1551000

= 2011647
