The number line estimation task is frequently used to measure children's numerical magnitude understanding. It is unclear whether the resulting straight, horizontal, left-to-right-oriented estimate patterns indicate task constraints or children's intuitive number--space mapping. Three- to six-year-old children (N = 72, M[subscript age] = 4.89, 56%…

Experimentally manipulating Approximate Number System (ANS) precision has been found to influence children's subsequent symbolic math performance. Here in three experiments (N = 160; 81 girls; 3-5 year old) we replicated this effect and examined its duration and developmental trajectory. We found that modulation of 5-year-olds' ANS precision…

Two experiments were designed to investigate the developmental trajectory of children's probability approximation abilities. In Experiment 1, results revealed 6- and 7-year-old children's (N = 48) probability judgments improve with age and become more accurate as the distance between two ratios increases. Experiment 2 replicated these findings…

The number line estimation task is widely used to investigate mathematical learning and development. The present meta-analysis statistically synthesized the extensive evidence on the correlation between number line estimation and broader mathematical competence. Averaged over 263 effect sizes with 10,576 participants with sample mean ages from 4…

Recent work has probed the developmental mechanisms that promote fair sharing. This work investigated 2.5- to 5.5-year-olds' (N = 316; 52% female; 79% White; data collected 2016-2018) sharing behavior in relation to three cognitive correlates: number knowledge, working memory, and cognitive control. In contrast to working memory and cognitive…

Children (n = 130; M[subscript age] = 8.51-15.68 years) and college-aged adults (n = 72; M[subscript age] = 20.50 years) completed numerosity discrimination and lexical decision tasks. Children produced longer response times (RTs) than adults. R. Ratcliff's (1978) diffusion model, which divides processing into components (e.g., quality of…

How does understanding the decimal system change with age and experience? Second, third, sixth graders, and adults (Experiment 1: N = 96, mean ages = 7.9, 9.23, 12.06, and 19.96 years, respectively) made number line estimates across 3 scales (0-1,000, 0-10,000, and 0-100,000). Generation of linear estimates increased with age but decreased with…

Cardinal-ordinal abilities and attentional preferences of kindergarten nonconservers, kindergarten conservers, and third grade conservers of number were compared by employing standarized versions of Piagetian cardinal-ordinal tasks and a triad preference task. (Author/JMB)

Children ranging in age from three to six years counted 7, 10, and 14 items arranged in columns or in rows. Developmental changes in the spatial strategy and the relation of strategy to accuracy were examined. (JMB)

Two studies trace children's acquisition of counting as a means to extract, compare, and reproduce number from arrays of objects. Study 1 examined 3-, 4-, and 7-year-olds' use of counting to compare and reproduce arrays numerically. In study 2, nine of the 3-year-olds from the study 1 were retested after 12 and 18 months. (Author/JMB)

In a replication study, children 3 and 4 years old were given verbal rule training in order to probe the importance of identity, reversibility, and compensation explanations in training number and length concepts. Among the results, as before, identity was found to be the most significant factor in conservation acquisition. (Author/RH)

Groups of eight- and ten-year-olds and adults visually searched for the presence of a target letter or number in fields of items that were either of the same or a different category (letter or number) than the target. (JMB)

Study tests four predictions derived from Piaget's cognitive theory. (CB)

Young children's understanding of correspondences and numerical differences between disjoint sets was studied in three experiments. Findings appeared to restrict the theory that young children are limited to perceptually based forms of mathematical reasoning. (Author/MP)

The relation of CA, MA, and IQ to conservation was examined by comparing the performance of bright, normal, and retarded children matched on the critical MA of six years. (Author)