This article presents findings from the first major study to investigate lexical variation and change in British Sign Language (BSL) number signs. As part of the BSL Corpus Project, number sign variants were elicited from 249 deaf signers from eight sites throughout the UK. Age, school location, and language background were found to be significant…

There is a strong research base on the underlying concomitants of early developing math skills. Fewer studies have focused on later developing skills. Here, we focused on direct and indirect contributions of cognitive measures (e.g., language, spatial skills, working memory) and numerosity measures, as well as arithmetic proficiency, on key…

This chapter situates fraction learning within the integrated theory of numerical development. We argue that the understanding of numerical magnitudes for whole numbers as well as for fractions is critical to fraction learning in particular and mathematics achievement more generally. Results from the Delaware Longitudinal Study, which examined…

Early number sense knowledge is highly predictive of later math achievement (Herbers et al., in press; Jordan, Kaplan, Ramineni, & Locuniak, 2009; Obradovic i et al., 2009). However, research suggests that variables beyond number competencies contribute to students' mathematics achievement, most notably, executive function (Blair & Razza,…

Reflecting concerns about student attainment and participation in mathematics and science, the Effecting Principled Improvement in STEM Education ("epiSTEMe") project attempted to support pedagogical advancement in these two disciplines. Using principles identified as effective in the research literature (and combining these in a novel…

Perceptual decision-making performance depends on several cognitive and neural processes. Here, we fit Ratcliff's diffusion model to accuracy data and reaction-time distributions from one numerical and one verbal two-choice perceptual-decision task to deconstruct these performance measures into the rate of evidence accumulation (i.e., drift rate),…

Working memory predicts children's reading comprehension but it is not clear whether this relation is due to a modality-specific or general working memory. This study, which investigated the relations between children's reading skills and working memory (WM) abilities in 3 modalities, extends previous work by including measures of both reading…