The use of the empty number line in England and the Netherlands

This paper contrasts the development of the Empty Number Line (ENL) in the Netherlands with its use in the teaching of mental calculations in England. In doing so the paper investigates the Dutch adoption of Soviet socio-cultural philosophies, in particular Gal’perin’s theory, and relates the notion of internalisation to the analysis of the ENL and its use within the English Primary National Strategy (PNS). By contrasting the English and Dutch approaches a better understanding of the specificity of the development of number sense in relation to mental calculation strategies is attained.