No problem, we've got 2103 and 3905 to multiply
2103 × 3905 = 3905 × (2103)
+ 3905 × 3 producing 11715
+ 3905 × 00 what gives us 0
+ 3905 × 100 producing 390500
+ 3905 × 2000 yielding 7810000

= 8212215
