No problem, we've got 3909 and 4815 to multiply
3909 × 4815 = 4815 × (3909)
+ 4815 × 9 what gives us 43335
+ 4815 × 00 that equals 0
+ 4815 × 900 that equals 4333500
+ 4815 × 3000 that equals 14445000

= 18821835
