Puzzle

The book “In code: A mathematical Journey” describes how Sarah Flannery got interested in mathematics from her early years. The book is about the learning process that finally led her to the discovery of a new and fast encryption algorithm in 1999, when she was only 17 years old. Although later the code was found to be breakable, her discovery at that age was a great achievement. In the book, she describes that one of the things that she enjoyed doing and made her interested in Math was solving puzzles. Puzzles are great for getting kids interested in logical thinking and math from the elementary school years to later in high school or even college. I am interested in learning effective ways to teach kids about math and science subjects. To teach them in a way which is interesting and which promotes deep and lasting understanding. One good resource for teachers and parents that I found are free online video workshops available at Annenberg/CPB . The “Looking at Learning” workshop series is excellent for a start.

Sarah Flannery’s book has many interesting puzzles including this one: Someone wanted to send his fiancé who lived in another city a ring. The post office was notorious for being corrupt and any package, which was not locked, would be opened and its content stolen. So he bought a padlock with a key and a box which had several latches. He called his fiancé and together they came up with a scheme to safely get the ring to her by mail. Considering the fact that even the key will be stolen if it is sent in an unsecured package, and assuming no one can open the padlock without a key and the box can not be broken, how were they able to do this?