ABSTRACT
This chapter draws on both quantitative and qualitative strands of data collected in mathematics classrooms for 9- and 10-year-olds in two socio-economically equivalent cities from two cultures and two countries. It correlates teacher behaviours with mathematics learning outcomes, captured multiple perspectives from different roles regarding the effectiveness of mathematics teaching within and across national borders and scrutinised the interconnections between hard measurement and soft voices. The chapter demonstrates an optimal utilisation of video in classroom observations, post-lesson interviews and focus groups. The use of video might not occur to be foreign for researchers in teaching effectiveness research (TER) and other communities in educational research. The replicated findings about what works in the mathematics classroom make a wakeup call to practitioners, policymakers, educational improvement researchers and all other educational stakeholders in both countries and beyond, regarding the possibility of making change in the teaching and learning of mathematics.
