No problem, we've got 6443 and 6503 to multiply
6443 × 6503 = 6503 × (6443)
+ 6503 × 3 that results in 19509
+ 6503 × 40 producing 260120
+ 6503 × 400 which equals 2601200
+ 6503 × 6000 resulting in 39018000

= 41898829
