We're going to solve 3996 multiplied by 3405
3996 × 3405 = 3405 × (3996)
+ 3405 × 6 producing 20430
+ 3405 × 90 which equals 306450
+ 3405 × 900 giving us 3064500
+ 3405 × 3000 that is equal 10215000

= 13606380
