No problem, we've got 2640 and 6815 to multiply
2640 × 6815 = 6815 × (2640)
+ 6815 × 0 that is equal 0
+ 6815 × 40 what gives us 272600
+ 6815 × 600 that results in 4089000
+ 6815 × 2000 that equals 13630000

= 17991600
