Alright, let's work through 8331 times 521 step by step
8331 × 521 = 521 × (8331)
+ 521 × 1 that results in 521
+ 521 × 30 yielding 15630
+ 521 × 300 that is equal 156300
+ 521 × 8000 that is equal 4168000

= 4340451
