Alright, let's work through 3106 times 4003 step by step
3106 × 4003 = 4003 × (3106)
+ 4003 × 6 resulting in 24018
+ 4003 × 00 that is equal 0
+ 4003 × 100 that results in 400300
+ 4003 × 3000 which equals 12009000

= 12433318
