Tamsin Meaney is professor of mathematics education at Bergen University  College, having previously been professor at Malmö University. She has worked in  teacher education in New Zealand, Australia, Sweden and Norway. Her research  interests are varied but centre around the need for mathematics education to  support social justice concerns. Whilst in Sweden she started the research  group, Young Children's Mathematics. Ola Helenius has a PhD in mathematics but in the last few years has worked  in mathematics education at the Swedish National Centre for Mathematics,  Gothenburg University, where he is currently deputy director. He is interested  in mathematics education at all levels and was part of the group who provided  advice for the development of the revised Swedish curriculum for preschools in  2010. He belongs to a number of research groups at different institutions across  Sweden and is also part of the Scandinavian research group, Young Children's  Mathematics. Maria L. Johansson has a PhD in mathematics and also one in mathematics  education. Her PhD in mathematics education focused on issues to do with  mathematics in preschool, particularly to do with the professional development  of preschool teachers and childcare workers. She is an Associate Professor at  Luleå University where she works in teacher education. Her research interests  are wide ranging, covering both mathematics and mathematics education for a  range of ages. She has also published extensively with the research group, Young  Children's Mathematics. Troels Lange has been a mathematics teacher education for twenty years,  first in Denmark, then Australia and Sweden. He currently works at Bergen  University College in Norway where he is an Associate Professor. His research  interests centre on how children experience learning mathematics but he has  published on a range of different issues to do with mathematics education. Since  2011, he has been part of and published with the research group Young Children's  Mathematics. Anna Wernberg is associate professor in mathematics teacher education in  the Faculty of Education and Society at Malmö University. She had previously  worked at Kristianstad University and Borås University, also in Sweden. Her  research interests focus on the use of learning studies in mathematics  classrooms for young children. She has also published extensively with other  members of the research group Young Children's Mathematics.