We're going to solve 5902 multiplied by 4003
5902 × 4003 = 4003 × (5902)
+ 4003 × 2 producing 8006
+ 4003 × 00 resulting in 0
+ 4003 × 900 which equals 3602700
+ 4003 × 5000 producing 20015000

= 23625706
