State tests are right around the corner, and educators are working hard to remind their students of everything they’ve learned this year. That’s no easy feat! The recent Edutopia article “Why Students Forget—and What You Can Do About It” suggests “making as many connections as possible—typically to other concepts” to keep lessons fresh in students’ minds. Most students won’t make these connections on their own, so it’s important for educators to make these connections explicit. An engineering design challenge can be an effective (and fun!) way to make explicit connections to math concepts and strengthen students’ math skills. As students walk through the engineering design process, excited to design and improve their own technologies, educators can encourage students to productively use math to solve the problem. Below, we highlight EiE units that have strong math connections to demonstrate how educators can reinforce math concepts in a way that will stick.