We're going to solve 3999 multiplied by 6441
3999 × 6441 = 6441 × (3999)
+ 6441 × 9 what gives us 57969
+ 6441 × 90 what gives us 579690
+ 6441 × 900 resulting in 5796900
+ 6441 × 3000 what gives us 19323000

= 25757559
