Dyscalculia: Memory for Math
When my research team interviewed Robert, a 10 year old, he was pleased to report that his memory for numbers is very good and he “can do 2, 5 and 10 times tables but 4 and 6 times tables are hard.” He said that if he can’t see the numbers he can’t remember them: “I need to have them written down because they don’t stay in my head.”
Like Robert, the student with dyscalculia has clear working memory deficits. However, the link between working memory and math skills depends on the age of the child as well as the type of math task. Verbal working memory plays a strong role in math skills in 7-year olds and is a reliable indicator of dyscalculia in the first year of formal schooling. Once children reach adolescence, verbal working memory is no longer significantly linked to mathematical skills. One explanation for this change is that verbal working memory plays a crucial role for basic arithmetic skills like learning arithmetic rules and retaining relevant data such as carried digits when they are young. However, as children get older other factors such as number knowledge and strategies play a greater role.
Visual-spatial working memory problems are also linked to dyscalculia. It has been suggested that visual-spatial memory functions as a mental blackboard to support number representation, such as place value and alignment in columns in counting and arithmetic tasks. We also use visual-spatial memory to solve multi-digit operations and problems presented visually, including those using blocks. Poor working memory is thought to be one explanation for dyscalculia because it limits their ability to remember mathematical rules, from basic concepts like counting in ascending and descending order, to more complicated algebraic functions.
