In our investigation of preservice secondary teachers' understanding of irrational numbers we focus on how different representations influence participants' responses with respect to irrationality. As a theoretical perspective we use the distinction between transparent and opaque representations, that is, representations that "show"…

There is a growing interest in the mathematics education community in the notion of abstraction and its significance in the learning of mathematics. "Reducing abstraction" is a theoretical framework that examines learners' behavior in terms of coping with abstraction level. This article extends the scope of applicability of this…

This study examined the problem-solving strategies and systematic errors of (n=82) preservice elementary school teachers related to place value concepts and decimal representations of rational numbers. Problems were posed in the unfamiliar domain of numeration systems with bases other than base ten. (Contains 13 references.) (MKR)

Investigated (n=124) preservice school teachers' reasoning and concepts of invariance of fractional numbers under numeration systems in different bases. The majority of students believed that fractions change their numerical value under different symbolic representations. (Author/MKR)

Recent research demonstrates that many issues related to the structure of natural numbers and the relationship among numbers are not well grasped by students. In this article, we describe a computer-based learning environment called "Number Worlds" that was designed to support the exploration of elementary number theory concepts by…