No problem, we've got 6105 and 4200 to multiply
6105 × 4200 = 4200 × (6105)
+ 4200 × 5 resulting in 21000
+ 4200 × 00 yielding 0
+ 4200 × 100 which equals 420000
+ 4200 × 6000 that results in 25200000

= 25641000
