Alright, let's work through 4991 times 4230 step by step
4991 × 4230 = 4230 × (4991)
+ 4230 × 1 giving us 4230
+ 4230 × 90 that equals 380700
+ 4230 × 900 giving us 3807000
+ 4230 × 4000 producing 16920000

= 21111930
