The paper describes the use of a spreadsheet in a mathematics teacher education course. It shows how the tool can serve as a link between seemingly disconnected mathematical concepts. The didactical triad of using a spreadsheet as an agent, consumer, and amplifier of mathematical activities allows for an extended investigation of simple yet intriguing properties of whole numbers. The authors argue that revisiting elementary content in a technological context enables pre-service teachers to appreciate the role that conceptual knowledge can play in the development of a spreadsheet-enabled pedagogy. (Contains 7 figures.)