Book excerpt: This versatile, economical book gives you two intriguing math riddles for every day of the year. Each puzzle highlights an interesting person or event associated with that particular day. Students guess the year based on mathematical clues such as, "The square root of my tens digit is equal to my units digit." In solving the puzzles, students work with a wide range of math concepts and functions. They interpret quantitative clues, use context clues to problem solve, and connect abstract number theory to a fun activity.