Abstract

This study compared number and area acuity between 4th and 6th graders, and examined whether number and area acuity predicts mathematical achievement after controlling for domain-general cognitive abilities. Participants were presented with a pair of dot arrays and were asked to choose the array with either larger set size (numerosity comparison) or cumulative area (area comparison). Within each grade, number and area acuity were significantly correlated. Although, number acuity was significantly higher in 6th compared to 4th graders. area acuity did not differ between grades. Math achievement was significantly predicted by number acuity in 4th, but not in 6th grade. The present study supports the idea that the acuity for continuous magnitude matures earlier than that for numerosity. Taken together with previous studies, our results suggest that number acuity may contribute to earlier mathematical achievement, but not to higher level, mathematical problem solving which requires more domain-general cognitive abilities such as working memory.