Early nonsymbolic proportional estimation strategies and their contributions to math achievement

Children possess remarkable proportional quantity skills; yet, their proportional estimations are often misguided by absolute quantities. Recent efforts have aimed to both quantify individual differences and identify possible erroneous strategies in proportional reasoning. We examined—across four time points over two years—the strategies pre-K-to-third-grade students used to estimate visually presented proportional quantities on a line and how their initial strategy related to their proportional reasoning growth and math ability. Results showed that individual differences are captured by strategy profiles that vary in the attended proportional or absolute quantity. Children who initially focused on proportional information maintained this strategy throughout the study and had stronger math ability than children who focused on one or two absolute quantities. Importantly, the absolute quantities children focused on were distinctly related to their estimation growth and math ability. These findings underscore the importance of considering quantitative and qualitative descriptions of children's proportional reasoning skills.