Alright, let's work through 1608 times 7421 step by step
1608 × 7421 = 7421 × (1608)
+ 7421 × 8 that is equal 59368
+ 7421 × 00 what gives us 0
+ 7421 × 600 producing 4452600
+ 7421 × 1000 that results in 7421000

= 11932968
