This paper aims to contribute to the advancement of methodological practice for phenomenographic research by introducing the notion of a "lens of awareness," as a device that can enable researchers to zoom into the detail of the research process (the parts of the whole) and out again to the related context of a phenomenographic study (the whole). The lens enables researchers to embrace a reflexive stance to bracket prior assumptions, allowing critical inspection of the whole research process and a thorough retrospective and transparent account of the approaches used. We use a "lens of awareness" to communicate the component parts of a study that examined preschool children's understandings of the use of numerals in everyday environments. Through an analytical documentation of processes and decisions, we examine challenges, the powerful affordances and application of a phenomenographic approach to research with young children. We discuss four strands of researcher awareness that we argue are important in the application of phenomenography: the nature of the phenomenon; the operationalization of phenomenographic theoretical notions; the researcher's versus the participant's experience of the phenomenon and the applied research processes. The paper closes with explorative strategies that may enhance transparency and trustworthiness in phenomenographic research.