On learning number: The ‘-ty’ and ‘-teen’ confusion

The aim of this paper is to draw out implications for the early learning of number from a detailed analysis of the work of one student, over an eight month period. The background to this work was our research interest in exploring the potential of approaching number without a focus on objects and cardinality, particularly for currently low-attaining students. We report on the difficulties that arose from a confusion of ‘-teen’ and ‘-ty’ numbers, for the student. We conclude that there is an argument for: (a) delaying work on ‘-teen’ numbers until students have worked on number structure more generally; (b) adopting a dual naming to regularise our naming system.