Planning effective, engaging lessons and units are challenging tasks for a teacher, but the process can also be meaningful and rewarding. Using a big understanding—a guiding statement describing essential content you want students to learn throughout the unit—teachers can successfully plan and create lessons around substantive science content while developing inquiry and literacy skills. In this article, the authors explore a way to both guide your planning and make learning relevant by constructing a big understanding from the unifying concepts of science and your state standards.