Alright, let's work through 6620 times 4285 step by step
6620 × 4285 = 4285 × (6620)
+ 4285 × 0 giving us 0
+ 4285 × 20 producing 85700
+ 4285 × 600 giving us 2571000
+ 4285 × 6000 giving us 25710000

= 28366700
