No problem, we've got 4260 and 1620 to multiply
4260 × 1620 = 1620 × (4260)
+ 1620 × 0 yielding 0
+ 1620 × 60 giving us 97200
+ 1620 × 200 which equals 324000
+ 1620 × 4000 yielding 6480000

= 6901200
