This paper reports on a study of nursery children's responses to number focused activities. Responses were analysed in terms of cognitive, physical, emotional and social aspects in order to gain insights into what engaged children in number learning opportunities. "Cognitive-emotional hooks" for number activities were identified, involving cognitive activities with associated emotional responses, for instance predicting was associated with the "cognitive thrill" of problem solving and risk taking. Other responses included an appreciation of incongruity associated with humour, resulting sometimes in children's number jokes. The children's interest in number learning for its own sake underlines a view of children as agents in their own learning, but also challenges the view that number activities have to be integrated in everyday activities in order to be meaningful to young children. Children's responses suggest strategies for planning number activities, including playful teaching approaches to foster children's positive attitudes to mathematical learning.