Purpose This paper describes and discusses aspects that affect research questions in a practice-based research study, where learning study is used as a framework. The purpose of this paper is to contribute to understanding of the process where teachers and a researcher collaborate in transforming practical teaching problems into research questions. Design/methodology/approach A case study is conducted. Data consist of field notes, logbooks, manuscripts and conference papers from two learning studies conducted in grade 4 by three teachers and one researcher, and notes from meetings in a subject-teacher group at the school. The analysis focuses on how the research questions emerge and change in relation to discussions among teachers and in the research group of teaching, previous research and learning theory. Findings Questions about students’ discernment of the structure in the base-ten system emerged in learning study 1 and in the subject-teacher group. Discussions of previous research and the didactical theory learning activity transformed the research questions in learning study 2, into focusing students’ theoretical knowledge, examining general structures in the base system, using learning models as tools. Conditions for identification of specific teaching problems and alternative theory in a learning study are discussed. Originality/value The explicit example where research questions are transformed can be used in further discussions and methodological questions regarding formulation of research questions in educational research. Discussions, specifically of transforming research questions, when learning study is used may be promoted.

Purpose – The purpose of this paper is to investigate what might be relevant to younger children’s understanding of a number line and how teaching can be designed according to variation theory to give pupils the opportunity to develop an understanding of the number line as a tool for mathematical thinking. Design/methodology/approach – A Learning Study was conducted by mathematics teachers at Sjöstadsskolan in Stockholm. Variation theory was used as a theory of learning. In order to use the number line as a tool in mathematical thinking, pupils have to discern what is important for this form of representation of the numeral system. Critical aspects from other studies with similar learning objects have been taken into consideration for pre-test design. These aspects supplemented and enhanced the analysis of the results and the results were consistent with earlier learning studies’. Findings – Four critical features, for younger pupils’ understanding of how the number line can be constructed, have been established in the study: the number line can have a different range (e.g. 0-20 or 30-60), correlation between the distance and value, two reference points are needed to place a third number and determine the scale, and the correlation between a part and whole. Originality/value – Learning Study is emphasized as a powerful and structured model for teacher driven research aiming to develop the praxis. The use of experiences and results from other studies is recommended.