Middle school mathematics teachers’ knowledge of integers

The current research aimed to unpack teachers’ knowledge of integers by investigating how they used the number line and counter models to represent the two meanings of division (i.e., partitive and measurement). The participants were three middle school mathematics teachers working in different cities in Türkiye. Data consisted of teachers’ written responses to an open-ended questionnaire consisting of four division operations and interviews conducted thereafter. Findings revealed that although two teachers could accurately model all division operations with the number line model, one teacher could neither provide a problem context nor a model displaying one of the division operations. For the counter model, only one teacher could accurately model all division operations in the questionnaire.