Within the general landscape of STEM, we chose to situate the present study in the content area of algebra. Algebra is widely recognized as a crucial peg in the trajectory of mathematical learning, because of the conceptual and procedural groundwork it lays for accessing higher mathematics and because it presents a shift in how students are expected to think mathematically (Kieran 1992). Algebra is often the first time students are introduced to some of the most important and useful ideas in the field of athematics, such as the concept of a “variable” or the generalization of patterns in generted data (Star & Rittle-Johnson 2009). However, students’ difficulties in algebra are well documented on both national and international assessments (e.g., Beaton et al. 1996; Blume and Heckman 1997; Lindquist 1989; Schmidt et al. 1999). For example, in the eight-grade data from the US National Assessment of Educational Progress [NAEP] show that students continue to struggle on very straightforward algebra problems: Only 59% of 8th graders were able to find an equation that is equivalent to n + 18 = 23, and only 31% of 8th graders were able to find an equation of a line that passes through a given point and with a negative slope (National Assessment of Educational Progress, Question Tool, 2011).