How to Make a Decoder

Place each of the bowls upside-down on a piece of paper. Use a pencil to trace the outer edges, which will provide the outlines for the circles. Cut both of the paper circles out by using the scissors.

Place the smaller paper circle centered on top of the larger circle and temporarily connect the two circles together with a paperclip. In the center of the smaller circle punch a small hole through both circles, insert the paper fastener and then spread both of the tabs so that they lay flat against the back of the larger circle. Once the paper fastener is securely in place the paperclip can be removed.

Draw evenly sized squares around the edge of both circles so that the squares align on both circles. There need to be 26 squares, which allow a square for each letter of the alphabet (see Reference 1).

Write the "cipher text" letters or symbols in the squares on the larger circle (see Reference 1). The letters that are written in the squares of the smaller circle will be used to decipher the message and write down the "plain text."

Use crayons and markers to decorate and personalize the paper decoder.

Create a secret message and then exchange it for another message that has been created by someone with a matching decoder wheel. Find the first letter or symbol of the secret message on the outer wheel of the decoder and write down the letter that is aligned with it on the inner wheel. Continue the decoding process for each letter or symbol until the secret code is solved.