Have you ever read a story or seen a movie or television show that involved a code? What is the process that you would use to decode a message? In this chapter's first activity, you will decode a message and write in a code used by Julius Caesar. Then you'll have the opportunity to invent your own code.

In this chapter you will learn: how to use variables and variable expressions how to perform operations with integers how to graph points in the coordinate plane how to solve a problem by looking for a pattern