The study by Geary, Hoard, and Bailey (2011) investigates fact retrieval deficits in low-achieving children and children with mathematical learning disabilities (MLD). Using four years of mathematics achievement scores, the researchers identified typically achieving children, low-achieving children with mild and severe fact retrieval deficits, and MLD children. Multilevel models were used to compare the development of retrieval competence, arithmetic procedure competence, fluency in processing quantities, and number line representation across grades. The findings revealed that the retrieval deficits of low-achieving children with severe fact retrieval deficits were as debilitating as those of MLD children and showed less improvement over time. These deficits were characterized by the retrieval of counting string associates while attempting to remember addition facts, suggesting poor inhibition of irrelevant information during retrieval. This suggests a specific form of working memory deficit that is not captured by standard working memory tasks. The deficits were not related to procedural competence, performance on other mathematical tasks, verbal or nonverbal intelligence, reading ability, or speed of processing. The study highlights the importance of understanding the nature of fact retrieval deficits in low-achieving children and MLD children to inform targeted interventions.The study by Geary, Hoard, and Bailey (2011) investigates fact retrieval deficits in low-achieving children and children with mathematical learning disabilities (MLD). Using four years of mathematics achievement scores, the researchers identified typically achieving children, low-achieving children with mild and severe fact retrieval deficits, and MLD children. Multilevel models were used to compare the development of retrieval competence, arithmetic procedure competence, fluency in processing quantities, and number line representation across grades. The findings revealed that the retrieval deficits of low-achieving children with severe fact retrieval deficits were as debilitating as those of MLD children and showed less improvement over time. These deficits were characterized by the retrieval of counting string associates while attempting to remember addition facts, suggesting poor inhibition of irrelevant information during retrieval. This suggests a specific form of working memory deficit that is not captured by standard working memory tasks. The deficits were not related to procedural competence, performance on other mathematical tasks, verbal or nonverbal intelligence, reading ability, or speed of processing. The study highlights the importance of understanding the nature of fact retrieval deficits in low-achieving children and MLD children to inform targeted interventions.