Each problem sheet contains a letter, solution, and an equation. The solution to the first problem is at the top of page 2, the solution to the second problem is at the top of page 3, and so on, until the last page, whose solution is at the top of page 1. After a student solves a problem, they will move to the next problem sheet that contains the correct solution, allowing them to check their own work as they move from problem to problem. The letters act as problem numbers (since students will start at different problems to begin) and spell out the answer to a riddle, giving students another way to check their work. Blank boxes represent spaces between words. Problem sheets should be randomly posted around the classroom, instead of being posted in order.