...Chompoo Lunsak; Maitree Inprasitha; Narumon Changsri; Ariya Suriyon; Masami Isoda; Anake Sudejamnong Purpose This case study examines how primary teachers develop Pedagogical Content Knowledge (PCK) on fractions within the Transformative Lesson Study incorporating Open Approach (TLSOA) model...

... and differences. Design/methodology/approach A research lesson study on fractions in the fourth grade was conducted. The approach was designed based on the theory of semiotic mediation (TSM) enriched by means of quaternary analysis and the variation pedagogy of CLS. In this study, qualitative methods were...