Number Sense Growth in Kindergarten: A Longitudinal Investigation of Children at Risk for Mathematics Difficulties

TLDR

The study tracked 411 kindergarteners (mean age 5.8) across four time points, controlling for gender, age, and reading skill, and applied growth‑mixture modeling to identify three distinct number‑sense development trajectories. Low‑income children scored lower than middle‑income peers at kindergarten’s end on all tasks, yet both groups showed comparable growth rates except for story problems where low‑income children progressed more slowly; when problems were presented nonverbally with visual cues, progress was similar, and boys performed slightly better overall.

Abstract

Number sense development of 411 middle‐ and low‐income kindergartners (mean age 5.8 years) was examined over 4 time points while controlling for gender, age, and reading skill. Although low‐income children performed significantly worse than middle‐income children at the end of kindergarten on all tasks, both groups progressed at about the same rate. An exception was story problems, on which the low‐income group achieved at a slower rate; both income groups made comparable progress when the same problems were presented nonverbally with visual referents. Holding other predictors constant, there were small but reliable gender effects favoring boys on overall number sense performance as well as on nonverbal calculation. Using growth mixture modeling, 3 classes of growth trajectories in number sense emerged.