No problem, we've got 2140 and 8780 to multiply
2140 × 8780 = 8780 × (2140)
+ 8780 × 0 what gives us 0
+ 8780 × 40 producing 351200
+ 8780 × 100 yielding 878000
+ 8780 × 2000 producing 17560000

= 18789200
