The goal of this instructional activity is for students to use manipulatives to add integers, creating concepts rather than memorizing rules. This instructional activity will be related to the 300 Spartans who battled the invading Persians at the Battle of Thermopylae, inspiring the hit movie "300" and Stephen Pressfield's historical fiction, The Gates of Fire. Interdisciplinary connections will be made to literature, theater, and history, discussing why Pressfield called this the most important battle in establishing and securing democracy in western civilization. This instructional activity is a base for many subsequent lessons including subtracting integers, combining like terms when simplifying algebraic expressions, and solving algebraic equations.This lesson plan was created as a result of the Girls Engaged in Math and Science, GEMS Project funded by the Malone Family Foundation.