Identifying the cognitive predictors of early counting and calculation skills: Evidence from a longitudinal study.

The extent to which phonological, visual-spatial short-term memory (STM), and nonsymbolic quantitative skills support the development of counting and calculation skills was examined in this 14-month longitudinal study of 125 children. Initial assessments were made when the children were 4 years 8 months old. Phonological awareness, visual-spatial STM, and nonsymbolic approximate discrimination predicted growth in early calculation skills.These results suggest that both the approximate number system and domain-general phonological and visual-spatial skills support early calculation. In contrast, only performance on a small nonsymbolic quantity discrimination task (where the presented quantities were always within the subitizing range) predicted growth in cardinal counting skills. These results suggest that the development of counting and the development of calculation are supported by different cognitive abilities.