At Bletchley Juniors Codebreaking Club this week we used a spiral code. The activity was the food chain. I encoded a chain of either three, four or five plants/animals/birds in the wrong order. After they had decoded the creatures, I gave the children pictures which they had to match to the creature, then put in the correct order. As the children became more confident I gave them spirals which went in a different direction. I even sneaked in a bit of Ancient Greek, explaining the meaning of phytoplankton and zooplankton.

We played Chinese Chequers again at our Adults Board Games Club this week, due to a change in people attending. We also played Zenix, a chain building game, and 3D Noughts and Crosses.

At Bletchley Juniors Codebreaking Club this week we explored codes using simple household items, namely a paperclip and some tracing paper.

For the paperclip code I had prepared lots of pairs of words e.g. blood and guts, skull and crossbones, Romeo and Juliet. I encoded each word on a separate piece of paper and mixed up all the words. After decoding the words the children (working in teams of two) had to match up their pairs.

For the second activity I chose the page of a book and traced over a sequence of letters which spelt out a question. After decoding the question, I gave the children a blank sheet of tracing paper and they encoded their answer, which I then decoded.