Teresa Rojano is Professor in the Department of Mathematics Education, Center of Research and Advanced Studies (Cinvestav) of the National Polytechnic Institute, Mexico.

List of Contributors. Foreword 1. Algebra Structure Sense: Conceptual Approaches and Elements for Its Development 2. Ideas of Structure in the History of Algebra and Its Teaching 3. Structure Sense at Early Ages: The Case of Equivalence of Numerical Expressions and Equalities 4. Developing Structure Sense with Digital Technologies: Introducing the MEx Platform 5. Transformational Algebra, Structure Sense, and Notes on a Semiotic Interpretation 6. Students' Justification Strategies on the Correctness and Equivalence of Computer-Based Algebraic Expressions 7. The Importance of Algebra Structure Sense for the Teaching and Learning of Mathematics 8. On the Connection of Structure Sense in Mathematics and Who Sees and Transforms It: Internal Structure, Visual Salience, and Transformative Algebra