Squaring special numbers (9's and final 7)

1. Choose a number with repeating 9's and a final 7.
2. The square is made up of:
   • the same number of 9's as there are repeating 9's
   • 4
   • the same number of 0's as there are 9's in the square
   • A final 9

   Example:

1. If the number to be squared is 9997:
2. The square has:

   same number of 9's as there are
   repeating 9's:              9 9 9
    4                                4
same number of 0's as 9's
   in the square                       0 0 0
a final 9                                    9

3. So 9997 x 9997 = 99940009.

   See the pattern?

1. If the number to be squared is 999997:
2. The square has:

   same number of 9's as there are
   repeating 9's:        9 9 9 9 9
    4                              4
same number of 0's as 9's
   in the square                     0 0 0 0 0
a final 9                                      9

3. So 999997 x 999997 = 999994000009.

Learn the pattern and it's easy!