“…The notion of didactic suitability is a tool that is widely used, firstly, to analyse didactic sequences (and their redesigns) that have been designed and implemented by teachers with a view to improving mathematics teaching (Breda, 2020;Morales-López & Font, 2019;Sousa, Gusmão, Font & Lando, 2020), and, secondly, to organize the reflections of future or active teachers on their own practice in teacher training programmes (Esqué & Breda, 2021;Giacomone, Godino & Beltrán-Pellicer, 2018;Morales-Maure, Durán-González, Pérez-Maya & Bustamante, 2019;Seckel & Font, 2020), since it allows teachers to engage in systematic reflection on the complexity of the mathematical objects they teach and the factors involved in studying these. This tool has also been used for the analysis and assessment of textbook lessons (Burgos, Castillo, Beltrán-Pellicer & Godino, 2020) and for the design and assessment of mathematical tasks .…”