Young engineers boost STEM skills as they complete one hands-on challenge after another—from constructing a spinning windmill to building a solvable maze! Students simply choose a challenge card, use the snap-together building pieces to engineer a solution…and then test their creation, revising and retesting until their design is successful. Our kit includes over 250 building pieces and 10 double-sided challenge cards with possible solutions on the back. Cards measure 8 1⁄2" wide.