50-Piece Marble Run & Roll Ball Building Blocks | Educational Construction & Puzzle Set for KidsDesign, build, and watch the balls roll with this exciting 50 Piece Marble Run Building Set! Kids can construct their own unique tracks with slides, funnels, and turns, then send the balls rolling down. It's a fantastic STEM toy that teaches basic physics in a fun, hands on way. BUILD YOUR OWN TRACKS: Includes 50 colorful pieces to create a variety of different marble run designs. STEM LEARNING: An interactive way to learn about gravity, momentum, and