Alright, let's work through 3355 times 4236 step by step
3355 × 4236 = 4236 × (3355)
+ 4236 × 5 that is equal 21180
+ 4236 × 50 that results in 211800
+ 4236 × 300 that results in 1270800
+ 4236 × 3000 giving us 12708000

= 14211780
