This article provides an example of the implementation of school-wide professional learning as part of an Australian Research Council grant and the Catholic Schools Parramatta Diocese (CSPD) called Exploring Mathematical Sequences of Connected, Cumulative and Challenging Tasks (EMC[superscript 3] ) (Sullivan et al., 2021). By using sequences of challenging mathematical tasks and the student-centred structured inquiry model (Sullivan et al., 2021) at the primary school level the authors were able to improve teaching and learning in mathematics across all grades. The reason for implementing mathematics professional learning via sequences of tasks was to improve students' working mathematical skills and to establish a positive mathematics learning culture for teachers and students. At the same time the aim was to build positive teacher and student attitudes and approaches to challenging mathematics tasks, (OECD, 2016) and make a positive impact on school mathematics data.