Alright, let's work through 8390 times 620 step by step
8390 × 620 = 620 × (8390)
+ 620 × 0 what gives us 0
+ 620 × 90 resulting in 55800
+ 620 × 300 that results in 186000
+ 620 × 8000 that results in 4960000

= 5201800
