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…

Infants' visual perception of number change was investigated in three studies. These studies focused on infants' perception of events in which the total number of objects in a small group was changed through addition of another object. Involving 60 infants 5 months of age, Study I attempted to determine whether subjects perceived the properties in…