No problem, we've got 9121 and 7840 to multiply
9121 × 7840 = 7840 × (9121)
+ 7840 × 1 yielding 7840
+ 7840 × 20 giving us 156800
+ 7840 × 100 what gives us 784000
+ 7840 × 9000 yielding 70560000

= 71508640
