The purpose of the current study was to examine dimensionality and concurrent validity evidence of the EARLI numeracy measures (DiPerna, Morgan, & Lei, 2007), which were developed to assess key skills such as number identification, counting, and basic arithmetic. Two methods (NOHARM with approximate chi-square test and DIMTEST with DETECT…

Evidence is presented for the immediate apprehension of exact small quantities. Participants performed a quantification task (are the number of items greater or smaller than?), and carry-over effects were examined between numbers requiring the same response. Carry-over effects between small numbers were strongly affected by repeats of pattern and…

Compares one study in which 5-year-olds and another in which adults quantified random patterns of dots under unlimited exposure duration. Data on operating ranges and rates for subitizing and counting are included. (JMB)

Some patterns resulting from certain operations on numbers are discussed, analyzed, and explained. A method for predicting the outcome of these operations for any number is developed.