In first grade we have been investigating the properties of light and sound, including vibration from sound waves (we made our own cup phones!) and the effect of different materials on the path of a beam of light. After students develop an understanding of light and sound, they were challenged to solve a design problem Mylo, Suzi, and Angelina face. In the story, the characters are lost and must use only the materials in their backpack to communicate over a distance by using light and/or sound. Students use the design process to sketch, build, test, and reflect on a device that solves this design problem.