Sunday, July 22, 2012

Program: Codes and Ciphers

The first program of July in my tween series was "Codes and Ciphers." Let me tell you, if I thought "Riddle Me This" was an easy, laid-back program, this was that times twenty. I don't even have that much to say about it because it was probably the most ridiculously simple yet still entertaining program I've done. Here's what I did.

I had four tables set up around the room with the afternoon's activities on them and one table with display books relevant to the topic. Of the four activity tables, one was different from the rest. The last table is where I set up the "craft" for the day: making cipher disks. Now, let me tell you, I don't think I'll EVER do that craft again. I went through 3 failed prototypes before the version I set upon the kiddos and even that one didn't work exactly as it should. The basic idea is two different size cardstock circles (one slightly larger than the other), each divided into 26 sections (my final version ended up having 27 sections). You poke a hole through the middles of the circles, write the alphabet along the edges, attach the two with a paper fastener, and voila! Cipher disk. Now you just spin the smaller circle around to create a new ciphered alphabet (i.e. line up "A" with "G" or what have you and it tells you how to replace all the other letters as well). It sounds like a simple thing but this caused the most frustration for me yet this summer. I wasn't satisfied with the final version because it is near impossible to poke a hole through the exact center of a small cardstock circle. If you don't get it in the exact center of both circles, the alphabets don't line up exactly, leading to cipher confusion. The kids didn't seem to complain about it, but it bothered me to no end.

The other three tables had messages in different kinds of codes and ciphers. Once decoded, the messages gave random trivia bits, but the kids didn't actually seem to care all that much about what they said; they just liked trying to decode them. The codes and ciphers I used were:

- the Caesar cipher: probably the oldest and simplest, this just involves shifting the letters of the alphabet a certain number of places to encode your message. For the program, I shifted 13 spots so "A" became "M".

- the keyword shift cipher: similar to the Caesar, this inserts a code word into the beginning of the ciphered alphabet. Our code word was stumped. So the alphabet looks like this:
You skip the letters used in the code word when filling in the rest of the alphabet.

- Morse code: this is pretty self-explanatory. I provided the Morse code alphabet and then the kids just had to find the letters to decode the message.

- the date shift cipher: to encode your message, write today's numerical date underneath it, repeating until you reach the end of your message.
722 1 2 722
Then, you move each letter the corresponding number of spaces, so the "L" would become "S", "I" would be "J", etc. To decode, you take the coded message, write the date underneath, and then shift each letter backwards that number of spaces.

- the Union Route cipher: this was probably the hardest one I put out for the kids because I first enciphered the message using the Caesar and then plugged it into the Union Route. The message appears as a block of letters:
A  B  C  D  E
F  G  H  I   J
K  L  M N O
P  Q  R  S  T
(The block might look different depending on how long your message is; you can add rows, but it should always have five columns.) The message is read by following this pattern: read up column 1, down column 2, up column 5, down column 4, and up column 3. So, for my program, the kids had to first follow the pattern and write out the message, then they had to use the Caesar cipher to decode what I'd written.

- the shopping list code: this is a tricky one if you don't know the secret. Your message is written into what looks like an ordinary shopping list. But, the number in front of each item tells you which letter you need to read the message. So, if your list starts with "4 tomatoes", your secret message begins with the letter "A".

- by the book: both parties must have the exact same edition of the same book (this was easy for me; I used one of our book club titles). The message is written in triplets of numbers (164-3-6); this is the key to decoding. The first number stands for the page number, the second for the line number, and the third for the word number. But, the code could be altered so the numbers stand for different things: paragraphs or letters, for example.

- Pigpen/Masonic cipher: apparently, the Freemasons came up with this to keep their rituals secret. It's a bit difficult to explain but the alphabet is written out in two 3x3 grids and two Xs. One grid and one X have dots in each space as well. Then the message is written using the symbol that corresponds to the space where the intended letter is found. You can see what it looks like here.

And that's it! I just let the kids work on decoding each message at their own pace, with plenty of help from my teen volunteers (and myself) when needed. They all worked diligently and quietly, some in groups and others individually. They probably could have stayed all afternoon if I had enough messages for them to decode! Have you tried a similar program?

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