Children skilled in mental abacus show enhanced non-symbolic number sense

Mental abacus is the mental arithmetic with the help of an imagined abacus. Children skilled in mental abacus have been shown to exhibit advantages in arithmetic abilities. The current study investigated whether children with high-level mental abacus ability could outperform controls in non-symbolic number sense, which is considered to be much fundamental for arithmetic development. One hundred and fifty children (75 children skilled in mental abacus and 75 controls) took part in this study. Children skilled in mental abacus completed a mental abacus level test. Two groups of children performed serial cognitive tasks, including non-symbolic number comparison, arithmetic, language, spatial processing, visual perception, attention, processing speed, working memory, and general intelligence. Results show that children skilled in mental abacus had better non-symbolic number sense than the controls after controlling for general intelligence. The significant group difference of non-symbolic number sense retained after further controlling for age, gender, all types of cognitive processing available and even arithmetic performance. A mediation model showed that the non-symbolic number sense partially mediated the group difference on arithmetic development. The results suggest that children skilled in mental abacus have enhanced non-symbolic number sense. These findings raise the possibility that mental abacus training could have a causal effect on children’s non-symbolic numerical skills.