Sending and receiving secret messages is great fun for kids. Here is an easy way to make a secret code device called a cipher wheel.
These directions are for a set of two identical cipher wheels, because both you and the person you are corresponding with will need a copy of the code. Use the compass to draw four circles. Make two circles with a diameter of 4 inches and two circles with a diameter 4 1/2 inches. If you would like to make them larger, you can. Just make sure that there is about half an inch difference in the diameter of the circles.
Cut out the circles and fastener them together at their centers with the paper fasteners.
Mark off 26 sections around the outside of the circles. If you want to use the protractor to help you with the spacing, each section will be approximately 14 degrees (13.8 degrees to be exact).
Write the alphabet from A to Z on the outside circle.
Write all the letters of the alphabet in random order on the inner circle. Make sure both cipher wheels are identical!
To use your cipher wheel, begin your secret message with two key letters. The first letter will be one on the outer circle, and the second will be the matching letter on the inner wheel. Keep the wheel in this position while you translate your message. The recipient of the message should know ahead of time that the first two letters of the message will be the "key" used to set the wheel to the same position the sender used.