Societal gaps and the importance of number sense. Research revealsthat low-income elementary students experience flatter number sensetrajectories than their peers and that number sense deficiencies are moreprevalent in low-income students (Jordan et al., 2007; Jordan et al., 2006;Jordan, Kaplan, et al., 2009; Jordan & Levine, 2009). A similar pattern ispresent for students with weak prior mathematics knowledge and pre-existingmathematics difficulties (Kikas et al., 2009; Morgan et al., 2011). This trend iscompounded at the middle school level by achievement declines oftenassociated with major alterations in material, pedagogy, expectations, andgeneral structure (Schielack & Seeley, 2010). NAEP research on eighth grademathematics revealed that mathematics students below the tenth percentile rankwho are placed in higher-level classes like Algebra I are more likely to be poor,35Black and Hispanic, have parents without the optimal knowledge or resourcesfor academic assistance, be enrolled in urban high-poverty schools, and haveless experienced and less qualified teachers (Loveless 2008, 2010).