Alright, let's work through 3099 times 4878 step by step
3099 × 4878 = 4878 × (3099)
+ 4878 × 9 that is equal 43902
+ 4878 × 90 what gives us 439020
+ 4878 × 000 that results in 0
+ 4878 × 3000 resulting in 14634000

= 15116922
