Keep your mind sharp all year long with Mathematics 2021: Your Daily Epsilon of Math , a 12 12 wall calendar featuring 12 images relating to math concepts Let mathematicians Rebecca Rapoport and Dean Chung tickle the left side of your brain by providing you with a math challenge for every day of the year . The solution is always the date; but the fun lies in figuring how to arrive at the answer, and possibly discovering more than one method of arriving there. Some of the most tricky problems require only middle school math applied cleverly. With entry-level algebra, word problems, math puns, and interesting math definitions thrown into the mix, this calendar should intrigue you for the whole year. End the year with more brains than you had when it began with Mathematics 2021: Your Daily Epsilon of Math .