Pattern blocks are inexpensive wooden, foam, or plastic manipulatives developed in the 1960s to help students build an understanding of shapes, proportions, equivalence, and fractions (EDC 1968). The colorful collection of basic shapes in classic pattern block kits affords opportunities for amazing puzzle-like problem-solving tasks and for exploring underlying mathematical relationships. These visuals can help build students' conceptual and procedural understandings of rational numbers (Reimer and Moyer-Packenham 2005). To illustrate the accessibility and challenges of problem solving with pattern blocks at the middle school level, the authors of this article present increasingly challenging problems. The problems described progress from constructing shapes with given proportions to creating arrangements with given percentage, fractional, and decimal quantities to building seven completely simplified representations of any given rational number.