No problem, we've got 4381 and 3970 to multiply
4381 × 3970 = 3970 × (4381)
+ 3970 × 1 yielding 3970
+ 3970 × 80 producing 317600
+ 3970 × 300 which equals 1191000
+ 3970 × 4000 what gives us 15880000

= 17392570
