In this article, we direct attention to what becomes critical in teaching activities for toddlers (1–3-year-olds) to learn the meaning of numbers. One activity we thoroughly exploreis interactive book reading, based on previous research indicating positive learning outcomes from this type of mathematical activity, as it has shown to simultaneously embracethe child’s perspective and encourage interaction and ‘number talk.’ A specially designedpicture book presenting small quantities was developed, and variation theory principleswere embedded in both the book design and the teaching acts. Through qualitative analyses, we aim to identify what is critical in the interactive book reading sessions for toddlersto discern essential aspects of numbers, with a specifc focus on the conditions for makingmodes of representations into resources for learning. Preschool teachers frequently readthe book to 27 toddlers over the course of a year. Video documentation of their readingsessions was analyzed, and exposed the signifcance of addressing the child’s perspectivewhen choosing what representation to emphasize and in what ways connections within andbetween representations can be made. Thus, the study contributes knowledge on the teaching of numbers with toddlers, and problematizes as well as extends the potential of interactive book reading as a quality-enhancing educational tool.