Students must match the expression (number sentence) that uses a variable with the correct value for that variable. Requires students to understand variables and how to find their values in number sentences that use addition, subtraction, multiplication, and division. Must be familiar with terms: sum, difference, product, and quotient. Can be used as a standard memory game (put cards face down and select 2 until you find a match) or modified memory game (place expression cards face up, and value cards face down). I have also passed all the cards out to students and then given them a time limit to "find their partner." Once partners are found, students sit down together. Answers are checked once all are matched.