Learning mathematics : constructivist and interactionist theories of mathematical development

Editorial. Cognitive Play and Mathematical Learning in Computer Microworlds L.P. Steffe, H.G. Wiegel. Exponential Functions, Rates of Change, and the Multiplicative Unit J. Confrey, E. Smith. Growth in Mathematical Understanding: How can we Characterise it and How can we Represent it? S. Pirie, T. Kieren. The Gains and the Pitfalls of Reification -- the Case of Algebra A. Sfard, L. Linchevski. Images of Rate and Operational Understanding of the Fundamental Theorem of Calculus P.W. Thompson. Negotiation of Mathematical Meaning and Learning Mathematics J. Voigt.