Since the 1980s, economists have begun to regard investments in education and research and development as a way to increase long-term growth. This "new growth theory" has contributed to the study of human capital formation (development of those intangible resources a population possesses, such as knowledge, skills, or experience) in past and present-day societies: To understand why societies experienced growth, it is crucial to understand the levels of education among the various groups. To this end, scholars have developed several indicators, such as literacy rates. Recently, scholars have tried to develop new ways to measure the level of education, particularly because it has since become apparent that the measures of literacy historically have not always been very accurate. Moreover, historians have begun to wonder whether literacy was the most important type of human capital: Were counting and calculating not more important for economic and technological development?

To measure numeracy, economists and economic historians have mainly used population surveys. These show that respondents have the tendency to state their ages as round numbers, ending in 0 or 5, in particular in developing areas. This phenomenon, known as "age heaping", suggests that many people may have been uncertain of their own exact age. Scholars assume that "age heaping" is closely related to unfamiliarity and hence, with the incapacity to count and calculate. Although a likely assumption is that of a strong correlation between literacy and numeracy, this was not necessarily true historically. In a sense, this should not be all too surprising because while people became literate through formal schooling, they had to acquire numeracy in practice. It is useful to study both literacy and numeracy as complementary indicators of human capital, and "age heaping" has proven to be a useful topic to study the level of numeracy over time.

In this article, we focus on the northern part of the Low Countries, which had already experienced a revolution in human capital before the eighteenth century: The level of numeracy in the Netherlands and Belgium was by the eighteenth century already much higher than elsewhere in Europe, and in fact it was even higher than in some regions elsewhere in the world today. Evidence has also been found for striking gender differences: Women did not heap as much as men, and when they did, they showed a preference for multiples of 12. Tine De Moor and Jan Luiten van Zanden ascribe this to the denominations used in the monetary system, and suggest that women learned to count in practice, on the work floor and at the market, where the decimal system had not been introduced until the nineteenth century.