Codes and ciphers are a fun and productive way to help your students work on their critical thinking skills. This packet contains information, charts, keys, and worksheets for four different code/cipher systems: Morse Code, The NATO International Spelling Alphabet, The Caesar Shift, and Navajo Code Talking. Each code system is provided with a brief history and explanation of use, as well as a practice sheet. Also included is a worksheet to construct a Caesar Shift Wheel and a complete answer key for all practice sheets. These resources can be used in connection with many social studies, language arts, and math standards, or just for fun!