1 x 2 x 3x 4 x 5 x 6 x 7 x 8 x 9 x 10

= (1 x 10) x (2 x 5) x 3 x 4 x 6 x 7 x 8 x 9

= 10 x 10 x 3 x 4 x 6 x 7 x 8 x 9

= 3628800

10000 + 20000 + 2543 + 125444

= 30000 + 2543 + 125444

= 32543 + 125444

= 157987