The mediating role of number-to-magnitude mapping precision in the relationship between approximate number sense and math achievement depends on the domain of mathematics and age

Approximate number sense (ANS) refers to the ability to approximately estimate and manipulate relatively large numerical quantity representations. An accurate ANS is hypothesized to facilitate a precise mapping between symbolic numbers and their corresponding magnitude and thereby can lead to an advantage in representing and working with symbolic numbers. This is referred to as the ANS mapping theory. ANS mapping is one of the mechanisms through which symbolic number meaning is thought to be learned. In the present study, we aimed to examine whether the mediating role of number-to-magnitude mapping precision differs depending on the domain of mathematics in adults and children. We found that mapping precision fully mediated the relationship between ANS acuity and math achievement in certain domains (Quantitative Reasoning in adults and Arithmetic in children). These results suggest that ANS acuity indirectly affects only certain domains of math achievement through its contribution to number-to-magnitude mapping precision, and that mapping precision differentially contributes to distinct domains of mathematics throughout development.