Alright, let's work through 2100 times 4678 step by step
2100 × 4678 = 4678 × (2100)
+ 4678 × 0 what gives us 0
+ 4678 × 00 what gives us 0
+ 4678 × 100 yielding 467800
+ 4678 × 2000 producing 9356000

= 9823800
