No problem, we've got 4920 and 1641 to multiply
4920 × 1641 = 1641 × (4920)
+ 1641 × 0 producing 0
+ 1641 × 20 which equals 32820
+ 1641 × 900 that equals 1476900
+ 1641 × 4000 that is equal 6564000

= 8073720
