Here's another riddle.. . :) Perhaps technology has changed since it was written!
"Secret Message"
"Connie needs to send a secret message in a box to Neville at the other side of town. They both have a padlock, but for security reasons, they only have keys for their own padlocks. How can...
This is one way to do it. Probably the most straight forward. :)
1. Draw up a table - 7 squares by 7 squares.
2. Leave the first square blank.
3. Then write 1 - 6 across the table and 1 - 6 down the table... :)
4. Then complete each addition required until you have completed the table...