No problem, we've got 8440 and 8428 to multiply
8440 × 8428 = 8428 × (8440)
+ 8428 × 0 resulting in 0
+ 8428 × 40 which equals 337120
+ 8428 × 400 that is equal 3371200
+ 8428 × 8000 that results in 67424000

= 71132320
