Based on a study with six elementary school teachers and 115 students in grades 3, 4, and 5, this article discusses ways that teachers might support an understanding of variable as students explore pattern-finding activities. The practices emerged from interviews with teachers and a yearlong observation of teaching algebraic thinking during an afterschool program at six elementary schools. The task discussed here can be accessible to elementary school students. It supports understanding of different facets of a variable, thereby avoiding misconceptions that students usually have in later grades and allowing flexible understanding that is a core for algebraic thinking (Ursini and Trigueros 2001).