Seventy-seven children (ages 5-13) with mild to moderate mental retardation were presented with addition problems. The patterns of strategies used were found to be similar to those used by intellectually normal children, though counting-on and memory strategies were used by subjects with greater frequency. Strategies became more sophisticated with…

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…

Limitations of the retrieval strategy dimension of Siegler's (1982, 1984) distributions-of-associations model of young children's estimation of sums are delineated, an alternative model is described, and findings of two studies designed to test key assumptions of the models are reported. In Study 1, kindergarten children with normal IQ and no…

Students in grades 1, 3, 4, 5, 6, and college were timed as they produced the answers to simple addition problems or verified a given problem as true or false. First graders clearly relied on a counting process for their performance, as advanced by the Groen and Parkman "min" (for minimum addend) model. Third grade appears to be a…