This paper considers the role of school programming using the BOXER en
vironment. It gives details of a two-year research project in which a
group of primary school children (aged 9 - 11) developed their underst
anding of number through programming in BOXER. It argues that such pro
gramming should be regarded as a new form of literacy and as such, dev
eloped in concert with subject knowledge, and evaluated over the whole
of schooling.