The move towards “Algebra for All” is based on the notion that success in Science, Technology, Engineering, and Mathematics (STEM) competencies in the 21st century, require fluency in algebraic reasoning and problem solving. Although there is a great need for more students to join the STEM fields, few students pursue these fields in higher education. Scholars have proposed that algebraic thinking should be introduced in the early grades to make the transition to learning complex algebra easier (e.g., Blanton & Kaput, 2011; Cai & Knuth, 2011). Indeed, research has shown that it is possible for students in the earlier grades to engage in functional thinking (Warren, Cooper, & Lamb, 2006), and algebraic reasoning (Bjuland,
