Sometimes a student's unexpected solution turns a routine classroom task into a real problem, one that the teacher cannot resolve right away. Although not knowing the answer can be uncomfortable for a teacher, these moments of uncertainty are also an opportunity to model authentic problem solving. This article describes such a moment in Zahner's class "Problem Solving for Teachers." Reconciling these solutions led the students and Zahner and Dent on a multiweek quest to understand what was going on. Ultimately, this process of inquiry was a powerful lesson about the problem-solving practices as envisioned in the NCTM's Standards (2000) and in the Common Core State Standards for Mathematics (CCSSI 2010).