Engineering is not a subject that has historically been taught in elementary schools, but with the emphasis on engineering in the "Next Generation Science Standards," curricula are being developed to explicitly teach engineering content and design. However, many of the scientific investigations already conducted with students have aspects of engineering design. This allows teachers to not only leverage existing materials but also their own experience and expertise to incorporate engineering design into classroom curricula. By engineering design, the authors are referring to the process of students engaging systematically in an iterative process to solve real-world problems. This process includes three components: defining and delimiting engineering problems, designing solutions, and optimizing the design solution. In this article, the authors share two examples of "classic" science lessons they have adapted to teach science content through engineering design. They also provide some more general strategies as to how to adapt science investigations to focus on engineering design.