Tutorial 79
Squaring special numbers (6's and final 5)
  1. Choose a number with repeating 6's and a final 5.
  2. The square is made up of:
    • same number of 4's as repeating 6's
    • same number of 2's as repeating 6's
    • a final 25

   Example:

  1. If the number to be squared is 6665:
  2. The square has:

    three 4's (same number as
          repeating 6's)        4 4 4
    three 2's (same number as
          repeating 6's)              2 2 2
    A final 25                              2 5

  3. So the square of 6665 is 44,422,225.

   See the pattern?

  1. If the number to be squared is 666665:

    five 4's (same number as
          repeating 6's)   4 4 4 4 4
    five 2's (same number as
          repeating 6's)             2 2 2 2 2
    A final 25                                 2 5

  2. So the square of 666665 is 444,442,222,225.