Ulrich Kortenkamp is professor of mathematics and mathematics education at the University of Education Karlsruhe. His research interests lie at the interface between mathematics, computer science and didactics of the sciences. Götz Krummheuer is a professor in the department of mathematics at the Institute for the Teachng of Mathematics at the University of Frankfurt, Germany.

• ​Instruction and Construction: Integrating Both Processes to Promote Quality Early Mathematics Education.- A Dance of instruction with construction in mathematics education.- The Roots of Mathematising in Young Children.- The first Discernment into the NMT-Family.- Developing Critical Thinking Skill in Mathematics Education.- Identifying quantities of representations - Children using structures to compose collections from parts or decompose collections into parts.- What kind of challenges do teacher students encounter with respect to kindergarten mathematics?.- A pilot Study of Exam Papers.- Reconstruction of folk pedagogy in interaction processes.- Children’s engagement with mathematics in kindergarten mediated by the use of digital tools.- Professionalization of Early Childhood Educators with a Focus on Natural Learning Situations and Individual Development of Mathematical Competencies.- Reconstruction of conjunctive realms of experiences in early learning processes.- The Interplay Between Gesture and Speech – Second Graders Solve Mathematical Problems.- Nice text by problem posing – two samples with many challenges.- The Relationship between cultural Expectation and the local Realization of a Mathematics learning Environment.- Early maths with multi-touch – an activity-theoretic approach.- How one preschool teacher recognises mathematical teaching moments.- Development of Geometric Competencies – Children's Conception of Geometric Shapes in England and Germany.- The elements of mathematical creativity and the function of the attachment style in early childhood.- Early enhancement of kindergarten children potentially at risk in learning school mathematics.- It is quite confusing isn’t it?.- Preschool children's performance and self-efficacy on mathematical and non-mathematical tasks.- Preschool teachers' knowledge and self-efficacy regarding counting and enumerating tasks.- Conceptualizing preschool teachers' knowledge andself-efficacy for teaching mathematics: The CAMTE framework.- Mathematical Situations Of Play And Explorations As An Empirical Research Instrument.- Play-based mathematics in kindergarten.