This is a Museum of Math Rosenthal Prize (innovation in mathematics) finalist lesson!

This lesson teaches students how to decrypt a message written in a Caesar Cipher using frequency analysis. Students only need to know how to fill out a histogram, which can be itself part of the lesson. The lesson starts with the history of the first encrypted messages and finally challenges students to be a World War II codebreaker. Whichever pair can decode the messages first will succeed!

Perfect observation lesson! Focus on productive struggle, history in math, and ties to ELA (all messages are the introduction to famous books).

Customizable!