We're going to solve 6487 multiplied by 6391
6487 × 6391 = 6391 × (6487)
+ 6391 × 7 yielding 44737
+ 6391 × 80 what gives us 511280
+ 6391 × 400 that equals 2556400
+ 6391 × 6000 giving us 38346000

= 41458417
