October 28 of the Mystery Year is a day to remember English mathematician, John Wallis, credited for inventing the symbol for infinity. Clues for finding the year involve an equation with infinitely many solutions, repeating decimals, and square root. This puzzle provides engaging review for middle school or high school students to use any time. Your PDF download includes:2-page digital version with horizontal layout, prepped for Easel 1-page printable version4 pages of Teacher Notes including s