When “one, two, three” gains ordinal meaning: Investigating the development of numerical ordering skills in 3- to 5-year-old children.

= 4.08 years; 51% boys, 49% girls) using a task in which children ordered sets of items from least to most. Growth mixture modeling revealed varying rates of development in numerical ordering skills. Steep development in numerical ordering skills was associated with higher cardinality skills and number sequence production. Video analysis showed that mainly children who performed well in numerical ordering tasks used their knowledge of the number sequence to determine the order of the sets. These results suggest that numerical ordering skills emerge after cardinality and number sequence skills, potentially requiring the integration of both. (PsycInfo Database Record (c) 2026 APA, all rights reserved).