We're going to solve 4021 multiplied by 1290
4021 × 1290 = 1290 × (4021)
+ 1290 × 1 what gives us 1290
+ 1290 × 20 that results in 25800
+ 1290 × 000 producing 0
+ 1290 × 4000 resulting in 5160000

= 5187090
