Stephen R. Campbell

This paper explores how a young child (56 m) builds an understanding of the cardinality principle through communicative, touchscreen-based activities involving talk, gesture and body engagement working via multimodal, touchscreen interface using contemporary mobile technology. Drawing upon Nemirovsky's perceptuomotor integration theoretical lens and other foundational aspects of Husserlian phenomenology, we present an in-depth case study of a preschool child developing mathematical expertise and tool fluency using an iPad application called TouchCounts to operate with cardinal numbers. Overall, this study demonstrates that the one-on-one multimodal touch, sight and auditory feedback via a touchscreen device can serve to assist in a child's development of cardinality.

This study investigates procedural and conceptual aspects in preservice elementary school teacher's understanding of the Fundamental Theorem of Arithmetic. The data were collected by the means of a written questionnaire and individual interviews. The results suggest that the idea of the uniqueness of prime decomposition is very difficult to grasp. Participants' responses indicated, either implicity or explicity, that a possibility of alternative prime decompositions was often not overruled, and this influenced students' ability to make inferences regarding factors and divisors of natural numbers. Some pedagogical implications are discussed.

This study contributes to a growing body of research on teachers' content knowledge in mathematics. The domain under investigation was elementary number theory. Our main focus concerned the concept of divisibility and its relation to division, multiplication, prime and composite numbers, factorization, divisibility rules, and prime decomposition. We used a constructivist-oriented theoretical framework for analyzing and interpreting data acquired in clinical interviews with preservice teachers. Participants' responses to questions and tasks indicated pervasive dispositions toward procedural attachments, even when some degree of conceptual understanding was evident. The results of this study provide a preliminary overview of cognitive structures in elementary number theory.

Although representation and visualization are assumed to be at the core of understanding in Mathematics, history shows that visual impairments in general, and blindness in particular, are not irrevocable impediments to learning mathematics. In this paper, adopting Vigotsky’s mediation theory, we discuss how an undergraduate blind student demonstrates that lack of access to the visual field, does not impede his ability to visualize, but, rather, modifies it.