Alright, let's work through 6240 times 6140 step by step
6240 × 6140 = 6140 × (6240)
+ 6140 × 0 what gives us 0
+ 6140 × 40 producing 245600
+ 6140 × 200 producing 1228000
+ 6140 × 6000 what gives us 36840000

= 38313600
