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Learning Mathematics: The Cognitive Science Approach to Mathematics Education What 'Algebra' Should Students Learn?, Journal of Mathematical Behaviour, vol.5, pp.21-24, 1986. ,

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Language and Mathematics The discovery of grounded theory: Strategies for qualitative research Tapping into Algebraic Variables Through the Graphic Calculator, Issues in Teaching Mathematics Constructivism: A Way of Knowing and Learning Proceedings of PME 21 Success and Failure in Mathematics: the flexible meaning of symbols as process and concept, pp.9-16, 1967. ,

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Using Supercalculators to Affect Change in Linear Algebra The status and understanding of generalised algebraic statements Algebraic thinking in high school students: Their conceptions of generalisation and justification The arithmetic connection, Technology in Mathematics Teaching -a bridge between teaching and learning Proceedings of PME 11, pp.316-323, 1987. ,

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The variable-reversal error among five cultural groups New Technology and Mathematics Education: New Secondary Directions Issues in Teaching Mathematics Students' understanding of literal algebraic equations and formulae Psychodynamics of Mathematics Texts, Proceedings of PME 7, pp.180-188, 1983. ,

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Cognitive Technologies for Mathematics Education Error patterns and strategies in algebraic simplification The role of formal and non-formal thinking in doing algebra, Cognitive Science and Mathematical Education Proceedings of PME 11, pp.89-122, 1979. ,

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