Used Wynn's (1992) procedure in 3 experiments to test 5-month-olds' looking-time reactions to correct and incorrect results of simple addition and subtraction transformations. Found non-systematic evidence of either imprecise or precise adding and subtracting in young infants. Results suggest that infants' reactions to displays of adding and…

Maintains that findings showing numerical computation abilities in infants are considerably more robust and consistent than Wakeley, Rivera, and Langer suggest. Asserts that all the interim replication attempts have successfully replicated Wynn's original findings. Discusses possible reasons for failure to replicate in Wakeley et al. experiments.…

Asserts that findings on whether young infants look longer at incorrect addition and subtraction have been inconsistent or negative. Hypothesizes that imprecise ordinal calculating with very small numbers of objects develops in late infancy and that precise calculating develops in early childhood. (Author/KB)

Developmental changes in 5- to 7-year-old children's mental representation of addition and subtraction events were examined by means of the response times required to answer more or less questions. (Author/JMB)

Issues include consistent individual differences in children's strategy choices, interpretation of differences within a framework, and the relation of differences to standardized test performance. (RJC)

Examined Korean second and third graders' understanding of multidigit addition and subtraction. Korean children showed exceptional competence in multidigit addition and subtraction, and their solutions were based on quantitative understanding of multidigit numbers. Results are compared to the literature on the performance and conceptual structures…