This article reconsiders Case's theory of central conceptual structures (CCS), examining the relation between working memory and the acquisition of quantitative CCS. The lead hypothesis is that the development of working memory capacity shapes the development of quantitative concepts (whole and rational numbers). Study I, with 779 children from…

In this article, the authors summarize results from 5 randomized controlled trials assessing the effects of intervention to improve the fraction performance of fourth-grade students at risk for difficulty in learning about fractions. The authors begin by explaining the importance of competence with fractions and why an instructional focus on…

The purpose of the study was to determine whether individual differences in at-risk 4th graders' language comprehension, nonverbal reasoning, concept formation, working memory, and use of decimal labels (i.e., place value, point, incorrect place value, incorrect fraction, or whole number) are related to their decimal magnitude understanding.…

We report on the 1st experimental elicitation of nonbelieved memories for childhood events in adults (Study 1) and children (Study 2) using a modified false memory implantation paradigm. Participants received true (trip to a theme park) and false (hot air balloon ride) narratives and recalled these events during 2 interviews. After debriefing, 13%…

The purpose of this study was to examine the cognitive predictors of calculations and number line estimation with whole numbers and fractions. At-risk 4th-grade students (N = 139) were assessed on 6 domain-general abilities (i.e., working memory, processing speed, concept formation, language, attentive behavior, and nonverbal reasoning) and…

This study explored the Junior Brixton Test (JBT), an executive function (EF) measure for children, in comparison to the Wisconsin Card Sorting Test (WCST) in a sample of 6- to 8-year-olds, all attending the first 2 years of elementary school. Factor analyses indicated two main domains in both measures, namely concept formation and cognitive…

The main purposes of this study were to test the effects of teaching at-risk 4th graders to provide explanations for their mathematics work and examine whether those effects occur by compensating for limitations in cognitive processes. We randomly assigned 212 children to 3 conditions: a control group and 2 variants of a multicomponent fraction…

Before starting school, many children reason logically about concepts that are basic to their later mathematical learning. We describe a measure of quantitative reasoning that was administered to children at school entry (mean age 5.8 years) and accounted for more variance in a mathematical attainment test than general cognitive ability 16 months…

Developmental predictors of children's fraction concepts and procedures at the end of fourth grade were investigated in a 2-year longitudinal study. Participants were 357 children who started the study in third grade. Attentive behavior, language, nonverbal reasoning, number line estimation, calculation fluency, and reading fluency each…

Contributions of domain-general and domain-specific numerical competencies were assessed on first graders' number combination skill (NC) and word-problem skill (WP). Students (n = 205) between 5 and 7 years of age were assessed on 2 aspects of numerosity, 8 domain-general abilities, NC, and WP. Both aspects of numerosity predicted NC when…

We investigated the relation between children's numerical-magnitude representations and their memory for numbers. Results of three experiments indicated that the more linear children's magnitude representations were, the more closely their memory of the numbers approximated the numbers presented. This relation was present for preschoolers and…

Tested the hypothesis that fourth-graders have a greater tendency than first-graders to represent transformations as ordered series of beginning, middle, and end states. Predominantly constructed states of fourth-graders were components of continuous movements or transformations, whereas those of first-graders related to the experimenters' on the…

The Piagetian concept of horizontality was studied in 195 fifth graders to determine the relationship between this concept and memory. (ST)

False recognition errors in elementary school children were studied using word association tasks. Data obtained validated the developmental changes in the dominant dimensions of associative organization. (ST)

Recognition errors of children in Grades 2, 4, and 6 were examined. Subjects learned words under intentional or incidental instructions and were tested immediately or 48 hours later. Subjects had to choose a target word from among acoustic, conceptual, associative and neutral distractors. The immediate recognition of 2nd-grade subjects was…