Difficulties in mathematics are argued to stem from impairments of a specialized system of numerical magnitude representation. This study investigates whether different measures of numerical magnitude understanding in kindergarten uniquely predict mathematical achievement concurrently and 6 months later, and also examines the relative explanatory…

Using multitrait, multimethod data, and confirmatory factor analysis, the current study examined the effects of arithmetic item formatting and the possibility that across formats, abilities other than arithmetic may contribute to children's answers. Measurement hypotheses were guided by several leading theories of arithmetic cognition. With a…

The mathematical performance of 182 third and fourth graders in 8 different areas of mathematics was examined. The children belonged to 4 achievement groups: children with mathematic difficulties (MD only), children with both mathematic and reading difficulties (MD-RD), children with reading difficulties (RD only), and normally achieving children…

Two experiments involving a total of 40 three and 39 four year olds were undertaken to determine subjects' ability to sort and compare numbers according to magnitude. Results indicate that readiness skills for early childhood mathematics education should include development of appropriate concepts of number magnitude. (TJH)

Developmental differences in reasoning ability and item processing demands are analyzed in a study of cognitive determinants of number analogy performance in two IQ levels of elementary school children and college students. The amount of solution-related information in working memory was the crucial processing demand. Process differentiations of…