No problem, we've got 2640 and 7080 to multiply
2640 × 7080 = 7080 × (2640)
+ 7080 × 0 that equals 0
+ 7080 × 40 what gives us 283200
+ 7080 × 600 giving us 4248000
+ 7080 × 2000 that results in 14160000

= 18691200
