The current study examined the development of two effects that have been found in single-digit multiplication errors: relatedness and distance. Typically achieving (TA) second, fourth, and sixth graders and adults, and sixth and eighth graders with a mathematics learning disability (MLD) performed a verification task. Relatedness was defined by a…

When solving basic number fact problems (e.g., 4x5=20), students with mathematical learning disabilities (MLDs) make qualitatively different kinds of errors than both typically achieving and low-achieving students. This study explores the origin of these qualitative differences through a detailed analysis of one student with an MLD. Data were…