This chapter demonstrates how mathematics entails a process of translating real-life narratives or observations into the formal language of mathematics. This is a process of translation because mathematics is the formalization of non-formal interpretants. In other words, each mathematical equation or formulation is based on an incipient system of signs that was not mathematical in itself. The chapter then discusses a second translational movement in mathematics. Nadin argues that what he calls ‘ontology engineering’ is a next step in the translation process, in that mathematical equations and even real-life narratives have to be translated into the formal language upon which computers operate.