“…A review of research on proportional reasoning for middle school students that included comprehensive coverage of topics (e.g., ratios and proportions, scale drawings, percent, and percent of change) found only a few randomized controlled Tier-1 studies (Jitendra, Harwell, Dupuis, Karl, Lein, Simonson, & Slater, 2015; Jitendra, Harwell, Im, Karl, & Slater, 2018; Jitendra, Harwell, Karl, Simonson, & Slater, 2017; Jitendra, Star, Dupuis, & Rodriguez, 2013; Jitendra, Star, Rodriguez, Lindell, & Someki, 2011). These studies were conducted in one upper Midwest state (Jitendra et al, 2011, 2013, 2015) and two states in the Southeastern and Western regions of the United States (Jitendra et al, 2018; Jitendra, Harwell, Karl, et al, 2017) and tested the efficacy of SBI, an instructional program designed to help seventh-grade students make sense of their reasoning related to proportions in word problem contexts. SBI is an instructional approach that has its roots in schema theory and research on expert problem solvers and is guided by cognitive models of mathematical problem solving (see Marshall, 1995; Mayer, 1999).…”