Keep your text messages under wraps

Set and crack secret codes with theses clever cipher wheels. the exact centre of your large circle. Divide your circle in half, then quarters, then continue dividing each section until you have 32 (see picture 1). 3. Place the small circle on top of the larger one so that the centres match up. Put

YOU WILL NEED (for each wheel): Thin card; Scissors; A pen and a pencil; A split pin

1. What to do: Draw two circles on a piece of card, one 12cm in diameter, the other 10cm in diameter.

2. Take a ruler and find a split pin through the centre of both. Separate the legs of the pin.

4. Draw another circle about 1cm in from the edge of the small circle. Continue the lines from the large circle onto the small one (see picture 2). 5. Write the letters of the alphabet and numbers 1-6 around the edge of each circle (picture 3).

TO WRITE A CODE:

Turn the inner circle so that A lines up with another letter – for example D. Write your message using the letters on the outer wheel. For example: if A on the inner wheel lines up with D on the outer wheel, HELLO would be KHOOR.

Send the coded message to your friend. Tell them which letter to line up with A and they can use their own wheel to crack your code.