Elementary preservice teachers’ fraction-as-measure reasoning with a dynamic tool

This study was an examination of the fractional reasoning of elementary preservice teachers (PSTs) within the context of a dynamic digital environment known as Dynamic Ruler. Using an inductive content analysis approach, we administered four fraction-as-measure tasks to 142 PSTs and devised a comprehensive coding scheme to assess their fractional reasoning. The results showed that PSTs’ fractional reasoning could be categorized into five levels based on how they identified length units and coordinated the units. Notably, this study revealed that adjusting the size of the Dynamic Ruler through dragging could serve as a dynamic mediator, representing the conceptualization of fractions as a measure by identifying appropriate fractional units to measure a given length. We derived practical implications from our study to inform the design of mathematics pedagogy courses aimed at bolstering PSTs’ fractional reasoning.