Training on number comparison, but not number line estimation, improves preschoolers' symbolic approximate arithmetic.

• Training in number line estimation improves number line estimation processing. • Training in number comparison improves number comparison and number line estimation. • Number comparison is crucial for symbolic approximate arithmetic. Although the performance of number comparison and number line estimation are correlated with symbolic approximate arithmetic ability, it is unclear whether they contribute differently to it. We conducted a training study with 96 preschoolers using pre- and post-tests measuring number comparison, number line estimation, and symbolic approximate arithmetic tasks. Participants were randomly divided into three groups (number comparison training, number line training, and control). The children in the training groups were trained using board games. The results showed that the number comparison training group showed a greater improvement in symbolic approximate arithmetic than did the other two groups. Further, improvement in number comparison was only found in the number comparison training group, whereas improvement in number line estimation was found in both training groups. These results indicate that symbolic approximate arithmetic relies on number comparison processing more than on number line estimation processing in preschoolers. Moreover, the cognitive mechanisms that number comparison and number line estimation abilities depend on are not exactly the same. [ABSTRACT FROM AUTHOR]