In this chapter, we explore and propose that teachers undertake technological pedagogical reasoning, which can assist in deepening an understanding of how we can represent the knowledge base of teaching. Technological Pedagogical Content Knowledge, introduced in the publication of the Handbook of Technological Pedagogical Content Knowledge (TPCK) for Educators (AACTE Committee on Innovation and Technology, 2008), understood Shulman’s (1987) conceptualisation of pedagogical content knowledge (PCK) and his articulation of pedagogical reasoning and action, whereby teaching is emphasised as “comprehension and reasoning, as transformation and reflection” (p. 13). Almost three decades later, there continues to be research, opinion, debates, development of standards and reviews of teacher education, which attempt to identify and understand the knowledge base for teachers.