<p>The study objective was to characterise prospective secondary mathematics teachers’ articulation levels of mathematics teacher noticing. We consider the articulation of the relationships among noticing skills of attending, interpreting, and making decisions and the different elements prospective mathematics teachers observe in a mathematics teaching situation (the mathematical task, students’ mathematical thinking, student–teacher interactions, and the teacher’s subsequent actions). During their teaching internship (practicum), seven prospective secondary teachers wrote narratives about events that they had identified as particularly relevant in the course of the mathematics teaching. The analysis of the written narratives focused on the relationships between what the prospective teachers noticed and how they interpreted what they observed, leading to decisions on the subsequent teaching steps to follow, taking into account the meaning given to the situations. Four articulation levels were found, which were named as follows: lack of evidence of articulation, incipient articulation, limited articulation, and strong articulation. The study findings help us to understand how prospective secondary teachers learn to notice mathematics teaching in specific contexts. They illustrate the differences between describing different aspects in a situation, generating knowledge about the situation, and using this knowledge to decide about the subsequent teaching actions to adopt.</p>