Approximate processing of numerosities is a universal and preverbal skill, while exact number processing above 4 involves the use of culturally acquired number words and symbols. The authors first review core concepts of numerical cognition, including number representation in the brain and the influential view that numbers are associated with space along a "mental number line." Then, they discuss how cultural influences, such as reading direction, finger counting, and the transparency of the number word system, can influence the representation and processing of numbers. Spatial mapping of numbers emerges as a universal cognitive strategy. The authors trace the impact of cultural factors on the development of number skills and conclude that a cross-cultural perspective can reveal important constraints on numerical cognition."The standard horizontal number line is clearly a product of culture, as it depends on culture-specific conventions of a written numeral system. But it also depends on three innate faculties: our number sense, our sense of the space around us, and the visual imagery system. The representations of our number sense are mapped onto a horizontal line (or arranged in a row) to form an integrated system of numerical representations in the imagery system; when activated, the resulting image is integrated into the representation of egocentric space. So here we have an example of a basic resource of human intelligence that is the product of an interaction between cultural and innate endowments."Numbers are ubiquitous-among other things, they specify times, locations, and wealth; in industrialized countries people process numbers to plan their day, find their way, and calculate their pay, and in more remote places people often use numerosity to keep track of livestock, children, and food. Rarely do we stop to think what an amazing achievement these numerical skills constitute. Only a few hundred years ago a large percentage of the world's population was virtually innumerate and only a minority could deal with exact numbers and perform arithmetic tasks (Ifrah, 1998). Everyday numeracy is an impressive cultural achievement that has shaped how we think about numbers and numerosities in many ways. We learn number processing, and in particular arithmetic and higher mathematical skills, through formal instruction. Differences in numerical experiences between cultures provide us with an opportunity to understand the relationship between culture, cognitive development, education, and human cognition more generally and the influence of cultural factors on the mental representation of numbers in particular. The present article describes this multifaceted relationship.