No problem, we've got 6820 and 3420 to multiply
6820 × 3420 = 3420 × (6820)
+ 3420 × 0 which equals 0
+ 3420 × 20 what gives us 68400
+ 3420 × 800 which equals 2736000
+ 3420 × 6000 producing 20520000

= 23324400
