In experiments with teenagers in the United States, scientists discovered that children whose "approximate number system" (ANS) was highly developed were also good in school-taught mathematics from an early age.
abstract:The approximate number system (ANS) is a cognitive system that supports the estimation of the magnitude of a group without relying on language or symbols. The ANS is credited with the non-symbolic representation of all numbers greater than four, with lesser values being carried out by the parallel individuation system, or object tracking system.