How does one look for mathematical structure? Finding structure is a challenging yet accessible activity for all students. This article describes a lesson in which seventh graders engaged with mathematical structure. The setting was a seventh-grade prealgebra classroom in a suburban school. The classroom teacher was co-author Tatyana Finkelstein. Using classroom excerpts, the authors illustrate three lesson design practices that shed light on the kinds of tasks teachers can pose to support students in seeking and finding structure: (1) using routine exercises to scaffold the lesson, with an aim of helping students apply their prior knowledge to new situations; (2) creating space for students to use language to connect their informal knowledge with the more precise mathematical formulations; and (3) providing a mathematical storyline that students can unfold to develop a coherent picture of the underlying mathematical ideas.