The approximate system of numeration (ANS) theory and therefore the ANS mapping account are the foremost prominent theories on non-symbolic numerosity processing and symbolic number processing respectively, over the last 20 years. Recently, there's a growing debate about these theories, mainly supported research in adults. However, whether the ANS theory and ANS mapping account explain the processing of non-symbolic numerosity and symbolic number in childhood has received little attention. Within the current ERP study, we first examined whether non-symbolic numerosity processing in 9-to-12-year-old children (N = 34) is intuitive, as proposed by the ANS theory. Second, we examined whether symbolic number processing is rooted in non-symbolic numerosity processing, as proposed the ANS mapping account. ERPs were measured during four same-different match-to-sample tasks with nonsymbolic numerosities, symbolic numbers, and combinations of both. We found no evidence for intuitive processing of non-symbolic numerosity. Instead, children processed the visual features of non-symbolic stimuli more automatically than the numerosity itself. Moreover, children don't seem to automatically activate non-symbolic numerosity when processing symbolic numbers.
