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.