Introducing Caeser Ciphers to children in the range of 4th-6th grade comes with a challenge - mostly, attention span. While translating with a given cipher is quick and easy, how could you introduce the concept, through the form of a paper/asynchronous medium, of cracking codes, in a fun, non-tedious, engaging manner?
Also, any general ideas on cool things to include related to Caeser Ciphers in general?
Related questions
Teach the general concept of substitution ciphers by showing them "alien writing" where all the letters look different. Then do it with writing modern English with Norse runes (history). Have them make their own alien codes (art), perhaps in small groups. Have them write a message in their journals to their parents in the code.
Then mention that a particularly boring example was invented by some Caesar and it just shifts all the letters along by some number. Make a big deal about how boring it is compared to the cool cipher they came up with.
Then show how easy it is to crack the code by looking for the words "the" and "a". Share with them your theory that maybe the Roman Empire collapsed because they weren't as smart as your kids and people kept cracking their secret messages.
Leave a piece of paper with a horizontal line of allcaps cyphertext in the play area. Next to it is a transparency cut into a couple dozen vertical columns, each with an allcaps alphabet written on it. The cleartext names the location in which you've hidden treasure. Depending on the target audience it might be candy, or a voucher that can be used to end a class of yours 10 minutes early, or a cryptography book. If it hasn't been found after a week, you can write hints on pieces of paper left elsewhere.
Beware: I just pasted an a->h Caesar-encrypted phrase into ChatGPT's latest paid model and it solved it.
Two cardboard circles of different diameter pinned in the center so they can rotate. Each circle has an alphabet written. Implements all shifts, allows a game of "decipher as fast as you can, but you don't know the shift constant". Explain how the board works and how to make it, and in a week there will be pandemic of student-written notes passed to each other unreadable by teachers.