This chapter argues that school mathematics involves more than just the “performance” of students and that “working mathematically” means far more than being good at a specified set of skills, as well as more than being able to show mastery of various conceptual structures. It suggests that experienced teachers understand that the wellbeing of many students can diminish when they are asked to engage with mathematics learning. Underlying such engagement and hence mathematical performance is a command of a specific language that holds the conceptualizing process together. Moreover, of particular importance for this chapter are the values, and their language, that are embedded within mathematics and its pedagogy and how they can be invoked to enable better engagement, improved student wellbeing and consequently better performance.