No problem, we've got 1664 and 6870 to multiply
1664 × 6870 = 6870 × (1664)
+ 6870 × 4 that is equal 27480
+ 6870 × 60 giving us 412200
+ 6870 × 600 that equals 4122000
+ 6870 × 1000 yielding 6870000

= 11431680
