Alright, let's work through 4355 times 621 step by step
4355 × 621 = 621 × (4355)
+ 621 × 5 that results in 3105
+ 621 × 50 what gives us 31050
+ 621 × 300 giving us 186300
+ 621 × 4000 what gives us 2484000

= 2704455
