At birth, infant have basic numerical intuitions that allow them to comprehend quantities. This ability depends on the approximate number system (ANS). This thesis aimed to find the main predictors of mathematical achievement, to explore the ANS’s nature, and to test training programs involving the children’s basic numerical intuitions and designed to promote numerical learning. Many important cognitive factors are involved in numerical learning including ANS acuity, working memory (WM) and the precision of “mapping” symbolic numbers to their corresponding quantities. A first study examined the effects of WM, mapping and ANS on numerical learning (as measured by arithmetic tasks), and showed that at 5 years old, the two dominant predictors ...