Visual form perception supports approximate number system acuity and arithmetic fluency

Research has shown an association between understanding of the approximate number system (ANS) and mathematical achievement, however, the mechanism of the association remains unresolved. This study was conducted to test whether visuospatial tasks (typically based on visual form perception) may account for the association. A total of 271 children around 10 years of age were recruited from three primary schools in Beijing, China. The children were administered eight tasks to assess their visuospatial processing and arithmetic fluency, as well as their processing speed and nonverbal intelligence as cognitive covariates. Visual form perception scores were measured by a figure matching task and a visual short-term memory task and fully accounted for the correlation between ANS acuity and arithmetic fluency. Spatial processing scores as measured by a spatial short-term memory task and a mental rotation task were not significant in the correlation. The results suggest that visual form perception is the cognitive mechanism explaining the association between ANS acuity and arithmetic fluency. Only visuospatial processes that rely on visual form perception promote ANS and arithmetic fluency.