Learning of the mathematical number line has been hypothesized to be dependent on an inherent sense of approximate quantity. Children's number line placements are predicted to conform to the underlying properties of this system; specifically, placements are exaggerated for small numerals and compressed for larger ones. Alternative hypotheses…

The relationship between elementary operations underlying processing of numerical information and performance on psychometrically derived ability measures requiring processing of numbers but defining separate ability factors was studied for 102 Air Force recruits (54 males and 48 females). Patterns of convergent and discriminate relationships for…

To isolate the process deficits underlying a specific learning disability in mathematics achievement, 77 academically normal and 46 learning disabled (LD) students in second, fourth or sixth grade were presented 140 simple addition problems using a true-false reaction time verification paradigm. (The problems were on a video screen controlled by…

First-grade children at risk for a learning disability (LD) in mathematics, reading, or both were compared to a control group on experimental tasks assessing number comprehension and production skills, counting knowledge, arithmetic skills, working memory, and ease of retrieving information from long-term memory. Found different patterns of intact…

Over a 10-month period, normal children showed an increased reliance on memory retrieval and a decreased reliance on counting when they solved addition problems. There was an increase in speed of counting and of retrieving addition facts from long-term memory. Children with a mathematical learning disability showed no change in problem-solving…