The arithmetical performance of typically achieving 5- to 7-year-olds (N=29) was measured at four 6-month intervals. The same seven tasks were used at each time point: exact calculation, story problems, approximate arithmetic, place value, calculation principles, forced retrieval, and written problems. Although group analysis showed mostly linear…

Recent studies have documented an evolutionarily primitive, early emerging cognitive system for the mental representation of numerical quantity (the analog magnitude system). Studies with nonhuman primates, human infants, and preschoolers have shown this system to support computations of numerical ordering, addition, and subtraction involving…

The SNARC (spatial-numerical association of response codes) effect refers to the finding that small numbers facilitate left responses, whereas larger numbers facilitate right responses. The development of this spatial association was studied in 7-, 8-, and 9-year-olds, as well as in adults, using a task where number magnitude was essential to…

This experiment aimed to expand previous findings on the development of mental number representation. We tested the hypothesis that children's familiarity with numbers is directly reflected by the shape of their mental number line. This mental number line was expected to be linear as long as numbers lay within the range of numbers children were…

Proposes the hypothesis that preschoolers have number concepts based on the numbers 1-5 rather than on the decimal structure. Results suggest that children understand numbers to 5 as a privileged anchor. Proposes a new model for a representational system of numbers. (Author/DR)

Four experiments were conducted to study explanations of why children make relative number judgments inconsistent with their counting. Results are discussed in relation to judgments children make when they use matching, and in light of Klahr and Wallace's (1973) account of number development. (PCB)

Examined role of spontaneous gesture in 2- to 4-year-olds' counting and assessment of counting accuracy. Found that correspondence of children's speech and gesture varied systematically across age. Children adhered to one-to-one correspondence principle in gesture prior to speech. Counting accuracy related to correspondence of speech and gesture,…

Examined whether preschoolers could recognize numerical equivalence for comparisons involving sequentially presented sets. Found that children recognized numerical equivalence for static sets earlier than for sequential sets. Memory of the number of sequentially presented objects emerged earlier than memory for the number of sequential events.…

Understanding of the cardinality principle in children with Williams Syndrome (WS) was compared to that of typically developing children. Findings indicated that such understanding was extremely delayed in WS children and only at the level predicted by their visuo-spatial mental age. Findings suggested that visuo-spatial ability played a greater…

Studies five-year-olds' relative number judgements of small and large number displays with and without perceptual aids. Children were found to respond to local rather than global density differences and to benefit from the provision of perceptual aids on both small and large number displays. (Author/AS)

Two experiments investigated infants' sensitivity to amount of continuous quantity and to changes in amount of continuous quantity. Found that 6-month-olds looked significantly longer at a novel quantity than at the familiar quantity. Nine-month-olds looked significantly longer at an impossible event than at a possible event. Findings question…

First-grade children at risk for a learning disability (LD) in mathematics, reading, or both were compared to a control group on experimental tasks assessing number comprehension and production skills, counting knowledge, arithmetic skills, working memory, and ease of retrieving information from long-term memory. Found different patterns of intact…