Since many years, he is interested in the use of digital technologies in mathematics education and in teacher education. He wrote books about Algebra, Geometry, Calculus, and Computers in Mathematics Education. He contributed to many international conferences like ICME, PME, EARCOME or ICTMT. He was the chair of the technology-group of CERME and he is still the chair of the conference series "Mathematics Education in the Digital Age". He worked at the universities of Oldenburg, Gießen and, since the year 2000, at the University of Würzburg. At the moment, he gives lectures at the University of Ausburg.

**Keynote Speaker 2. **

**Prof. Dr. Laura Van Zoest, Western Michigan University, United States**

Prof. Dr. Laura R. Van Zoest is a professor of mathematics, specializing in mathematics education, in the Department of Mathematics at Western Michigan University. She specializes in secondary mathematics teacher education, focusing specifically on the process of becoming an effective mathematics teacher and ways university coursework can accelerate that process. Lines of research have included investigating the effect of reform curriculum materials on teacher development, the use of practice-based materials in university methods courses, and the cultivation of productive norms in teacher education. Her current NSF-funded work (buildingonmosts.org) focuses on conceptualizing the teaching practice of building on high-potential instances. Van Zoest has served as the principal investigator for research and professional development projects funded at over three million dollars and published in research and practitioner journals, including the Journal for Research in Mathematics Education, Journal of Mathematics Teacher Education, Teacher and Teacher Education, Mathematics Teacher Educator and the Mathematics Teacher. She was editor of Teachers Engaged in Research: Inquiry into Mathematics Practice, 9–12, guest co-editor of the ZDM: The International Journal on Mathematics Education focus issue Theoretical frameworks in research on and with mathematics teachers, and co-editor of Research Trends in Mathematics Education. She co-chaired the 2012 PME-NA conference hosted by WMU, served as chair of the steering committee of PME-NA, currently serves on the International Advisory Board for Research in Mathematics Education, and is chair of the Editorial Panel for Mathematics Teacher Educators.

**Keynote Speaker 3. **

**Prof. Dr. Gizem Karaali, Pomona College, United States**

Karaali’s mathematics research involves algebraic objects of Representation Theory and certain algebraic and combinatorial structures on them, which have deep geometric significance. Her scholarly interests include humanistic mathematics, pedagogy, and quantitative literacy, as well as social justice implications of mathematics and mathematics education. She is a founding editor of Journal of Humanistic Mathematics.