Alright, let's work through 8105 times 504 step by step
8105 × 504 = 504 × (8105)
+ 504 × 5 giving us 2520
+ 504 × 00 that is equal 0
+ 504 × 100 giving us 50400
+ 504 × 8000 that equals 4032000

= 4084920
