What does 11111x11111 equal?

11111 x 11111 = 123454321

1 1 1 1 1
x 1 1 1 1 1
_______________
1 1 1 1 1
1 1 1 1 1
1 1 1 1 1
1 1 1 1 1
+ 1 1 1 1 1
_______________
1 2 3 4 5 4 3 2 1