The cognitive predictors of computational skill with whole versus rational numbers: An exploratory study

The purpose of the present study was to explore the 3rd-grade cognitive predictors of 5th-grade computational skill with rational numbers and how those are similar to and different from the cognitive predictors of whole-number computational skill. Students (n = 688) were assessed on incoming whole-number calculation skill, language, nonverbal reasoning, concept formation, processing speed, and working memory in the fall of 3rd grade. Students were followed longitudinally and assessed on calculation skill with whole numbers and with rational numbers in the spring of 5th grade. The unique predictors of skill with whole-number computation were incoming whole-number calculation skill, nonverbal reasoning, concept formation, and working memory (numerical executive control). In addition to these cognitive abilities, language emerged as a unique predictor of rational-number computational skill.

Research highlights
► We explore the cognitive predictors of whole- versus rational-number computational skill.
► We assess 3rd-grade students on calculation skill and other cognitive variables.
► We assess whole-number and rational-number computational skill in the spring of 5th grade.
► Predictors of whole-number computation skill were calculation, nonverbal reasoning, concept formation, and working memory.
► In addition to these abilities, language emerges as a unique predictor of rational-number computation skill.