Alright, let's work through 9920 times 635 step by step
9920 × 635 = 635 × (9920)
+ 635 × 0 yielding 0
+ 635 × 20 producing 12700
+ 635 × 900 that is equal 571500
+ 635 × 9000 giving us 5715000

= 6299200
