"Splash!" is a mathematics unit for high-ability learners in kindergarten and first grade focusing on concepts related to linear measurement, the creativity elements of fluency and flexibility, and the overarching, interdisciplinary concept of models. The unit consists of 13 lessons centered on the idea of designing a community pool. Students examine the question of why we measure, the importance of accuracy in measurement, and the various units and tools of measurement. The unit presents a hands-on, constructivist approach, allowing children to build their knowledge base and their skills as they explore mathematical ideas through play and planned investigations. Students are involved in creative and critical thinking, problem solving, process skill development, and communication.