One of the capabilities needed for effective participation in modern society is numeracy, which is the ability to cope effectively with the mathematical demands of life. While the development of numeracy continues beyond the school years, schools nevertheless have a responsibility to provide opportunities for students to expand their numeracy expertise. In Australian schools, there is a renewed emphasis on numeracy brought about by the introduction of a new curriculum, teacher professional standards and measures of accountability. The first two of these developments provide an opportunity for teachers of all disciplines to increase their capacity to promote growth in the numeracy capabilities of their students. However, they will be unable to do this unless they see themselves as teachers of numeracy and have the capacity to embed numeracy into the subjects they teach. This theoretical paper extends existing knowledge on teacher identity by developing a conceptual framework for identity as an "embedder-of-numeracy" that recognises the complexity of teacher identity while at the same time is amenable to empirical studies. The framework is organised around five "domains of influence" (knowledge, affective, social, life history and context) and includes characteristics that evidence from the literature suggests greatly impact on this particular situated identity. Studies using this framework could inform the design of professional development to support teachers to develop an identity as an embedder-of-numeracy. The mechanism for developing the framework described in this paper could also be used to create frameworks to investigate teachers' other situated identities.