Number Sense as Situated Knowing in a Conceptual Domain

This paper presents a preliminary attempt to characterize number sense theoretically as a form of cognitive expertise. I propose a way to view conceptual domains using a metaphor of an environment in which one can know how to find resources and use them to make things. I discuss the domain of numbers and quantities as an example of a conceptual environment, and I interpret number sense as a set of capabilities for constructing and reasoning within mental models. This perspective provides reasons that support considering various aspects of number sense as features of students' general condition of knowing in the domain of numbers and quantities, rather than skills that should be given specific instruction. Some current trends in research about cognition and learning support this view of knowing in conceptual domains, including number sense.