In conjunction with local middle schools, the Make to Learn Lab in the School of Education and Human Development at the University of Virginia offered a two-week Summer Engineering Academy for students who completed an introductory engineering course during the previous school year. In that course, students worked with circuits and advanced manufacturing equipment to build artifacts, such as solenoids, motors, and speakers. One example of how engineering projects from the Academy were used as contexts for students' exploration of previous and new mathematics topics is shared here. In this example, students algebraically determined where to place frets on the fretboard of a stringed instrument they were designing and along the way made use of a fractional exponent that was beyond what they experienced in prior courses.