Squaring special numbers (9's and final 5)

1. Choose a number with repeating 9's and a final 5.
2. The square is made up of:
   • same number of 9's as there are repeating 9's
   • same number of 0's
   • a final 25

   Example:

1. If the number to be squared is 9995:
2. The square has:

   same number of 9's as
   repeating 9's:         9 9 9
same number of 0's as 9's
   in the square               0 0 0
a final 25                           2 5

3. So 9995 x 9995 = 99900025.

   See the pattern?

1. If the number to be squared is 999995:
2. The square has:

   same number of 9's as
   repeating 9's:        9 9 9 9
same number of 0's as 9's
   in the square                0 0 0 0
a final 25                              2 5

3. So 999995 x 999995 = 999990000025.