Symbolic versus non-symbolic training for improving early numeracy in preschoolers at risk of developing difficulties in mathematics

Background: Children's understanding of symbolic (e.g., Arabic digits) and non-symbolic (e.g., sets of dots) magnitudes plays a key role in their mathematics achievement, but only a few studies directly compared the effects of symbolic and non-symbolic interventions on mathematical abilities. Aims: This longitudinal study compared the impact of symbolic and non-symbolic trainings in a group of preschoolers at risk of developing difficulties in mathematics (RM), analyzing their post-intervention performance both in early math skills (last preschool year) and in mathematics achievement in 1st grade. Methods: Eighty-nine RM children and 66 typically developing controls were selected from among 604 preschoolers. RM children were assigned to three intervention conditions: no intervention, symbolic or non-symbolic intervention. Results: Results showed specific effects on tasks related to the training (e.g., effects of symbolic training on symbolic tasks) and some effects of generalization (e.g., effects of symbolic training on non-symbolic tasks). In 1st grade, children attending the symbolic intervention showed a mathematics achievement profile similar to that of typically developing peers. Conclusions: These results suggest the importance of training the symbolic processing of numbers at preschool age, allowing at risk children to catch up with their peers before entering formal schooling.