Alright, let's work through 5091 times 8405 step by step
5091 × 8405 = 8405 × (5091)
+ 8405 × 1 which equals 8405
+ 8405 × 90 resulting in 756450
+ 8405 × 000 which equals 0
+ 8405 × 5000 giving us 42025000

= 42789855
