With a broad understanding or definition of "work" as something that includes unpaid labour, this paper examines the relationship between numeracy and work, and analyses specific forms and constraints of workplace related numeracy. This is done by highlighting and commenting on existing literature that focuses on the role of workplace mathematics and the identification of vocational mathematics. Following a numeracy framework suggested by Goos et al. (2014), the paper analyses three case studies, and pays special attention to mathematical knowledge, dispositions to mathematics, and the role of tools in industrial contexts. Workplace related mathematics often mixes mathematical and extra-mathematical knowledge and procedures into one "instrument", hiding and/or changing mathematics as it is encountered in or known from classrooms. Insights gained from case studies are complemented by an analysis of the PIAAC survey study. The paper leads to four major results, including a comment on the use of the term "numeracy" and a remark on "critical orientation" of numeracy from a workplace perspective.