This 2–3 week Common Core-aligned mathematics unit on algebraic expressions allows for students to develop a deep understanding of what an expression is and how it can be used to represent a situation. Students start off by working with number expressions and analyzing the components and evaluating them. Then they study the meaning behind a variable and how it is used in an algebraic expression. Finally, they work to understand that two expressions that may look different can be equivalent. The goal is to give students a strong foundation in algebraic expressions before moving on to equations and inequalities. This performance task focuses on students applying their knowledge of representing a real-life situation with an algebraic expression, evaluating expressions under specific circumstances for a variable, and justifying how two expressions that look different can be equal.