Algebraic competence is a major determinant of college access and career prospects, and equal sign knowledge is taken to be foundational to algebra knowledge. However, few studies have documented a causal effect of early equal sign knowledge on later algebra skill. This study assessed whether second-grade students' equal sign knowledge…

Using a cluster-randomized controlled trial research design, this study investigates the effect of the first year of a three-year teacher professional development program on grades 1 and 2 student achievement in mathematics. Although the findings reported in the present report do not meet the standard cutoff for statistical significance (e.g., 95%…