Collects secret codes to solve, and provides clues on constructing and cracking common types.

This book includes more than 100 secret codes that at one point in history carried life-or-death messages. Here they are used in puzzles, just for fun. All kids need to break them in is the ability to read and count--and the determination not to give up.

Over 100 secret messages to solve and crazy codes to crack. Each story involves some sort of code, such as a mystery letter or secret message, which you need to crack to find the hidden meaning.