Alright, let's work through 5045 times 8638 step by step
5045 × 8638 = 8638 × (5045)
+ 8638 × 5 that results in 43190
+ 8638 × 40 that results in 345520
+ 8638 × 000 that equals 0
+ 8638 × 5000 yielding 43190000

= 43578710
