Arithmetic is a major mathematical focus in elementary school curriculum, and researchers such as Mason (2008) claim that "algebraic thinking is required in order to make sense of arithmetic" (p. 58). When adding, subtracting, multiplying, and dividing, learners must rely on a small set of fundamental properties also important for the study of algebra. In this article, explore how a teacher incorporates the Standards for Mathematical Practice (SMP) into her instruction to help young learners use representations, look for patterns, notice underlying mathematical structure, and begin to generalize relationships.