In this article we first review evidence for the approximate number system (ANS), an evolutionarily ancient and developmentally conservative cognitive mechanism for representing number without language. We then critically review five different lines of support for the proposal that symbolic representations of number build upon the ANS, and discuss…

The acquisition of number conservation is a critical step in children's numerical and mathematical development. Classic developmental studies have established that children's number conservation is often biased by misleading intuitions. However, the precise nature of these conservation errors is not clear. A key question is whether conservation…

In this article, we provide an overview of current knowledge on the underlying cognitive deficits associated with mathematics learning disabilities (MLD). We highlight difficulties surrounding the identification of MLD that include inconsistency in defining MLD, comorbidity with other disabilities, problems associated with assessment tools and…

Insights from both cognitive psychology and learning disabilities intervention research are presented to improve understanding of the processes by which number fact fluency develops. Discussion includes assessment guidelines and learning strategies such as counting all, counting on, and alternative groupings. (Author/JDD)

This report opens by asking how operations in general, and addition and subtraction in particular, are characterized for elementary school students, and examines the "standard" instruction of these topics through secondary schooling. Some common errors and/or "sloppiness" in the typical textbook presentations are noted, and…