We're going to solve 6639 multiplied by 4243
6639 × 4243 = 4243 × (6639)
+ 4243 × 9 yielding 38187
+ 4243 × 30 resulting in 127290
+ 4243 × 600 that is equal 2545800
+ 4243 × 6000 what gives us 25458000

= 28169277
