No problem, we've got 3437 and 1640 to multiply
3437 × 1640 = 1640 × (3437)
+ 1640 × 7 what gives us 11480
+ 1640 × 30 giving us 49200
+ 1640 × 400 that results in 656000
+ 1640 × 3000 which equals 4920000

= 5636680
