math 2013
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Jenny Jones, the instructor for the day, started off by teaching the students the concept of binary. The concept was introduced as a game - get five chairs and get a student to sit in each one. In this game, the student that was furthest to the right and sitting down had to stand up. After standing up, the student would tell everyone to his or her right to sit back down. The game went on until everyone was standing up. After the game was finished, the instructor talked to the class about how it exemplified how counting in binary worked. Using the "Number Base Clocks" activity on Interactivate, the students could more easily see how the "base two number system" worked, along with other different number systems. Keeping the theme of different number systems, the instructor then talked about a twenty-six based number system that is heavily used - the alphabet. While treating the alphabet as a number system, she then introduced the idea of taking the number each letter represented, and putting it through a function to alter what it was, which is called encrypting.

Next, the students were given a challenge using Interactivate's "Caesar Cipher II" tool. Their instructions were to input a phrase of their choosing, examine the output that was given, and figure out what the function was that encrypted the message. At the end of the challenge, the instructor had the class share what methods they used to try to crack the codes.