Summary The objective of this study was to examine the influence of the socio-economic status of children in kindergarten on the development of their early numerical skills and their spontaneous approach to numbers (SFON), after controlling by cognitive variables of general domain, such as labour intelligence and memory, and by age. When starting the children’s garden, 355 boys and girls resolved a set of tests to assess their early numerical skills, SFON, intelligence and work memory. The results indicate that there are individual differences in early numerical skills and SFON of Ecuadorian children at the start of the children’s garden. In addition, the socio-economic level was positively correlated with early numerical skills, but not with SFON. The theoretical, methodological and practical implications of the study are finally discussed.