Why numerical symbols count in the development of mathematical skills: evidence from brain and behavior

- Symbolic number knowledge mediates relationships between informal and formal mathematics.
- Numerical symbols should be emphasized in informal preschool activities.
- Future research should investigate mechanisms underlying acquisition of mathematical skills.

Numerical skills measured prior to school entry are predictive of mathematics achievement longitudinally. It is therefore important that young children start school with strong mathematical foundations. Here we review evidence from behavior and neuroimaging that highlights numerical symbol knowledge as a key mediator between informal and formal mathematical competencies. We argue that future research should aim to elucidate cognitive and neuronal mechanisms underpinning the acquisition of symbolic knowledge. Furthermore, multiple aspects of numerical symbol knowledge, such as identification, cardinality, and ordinality, should be emphasized in preschool childcare environments.