Discover gravity in motion with the Discovery Classic Marble Run. This 58-piece STEM construction set includes 52 interlocking track pieces and 6 marbles for hours of creative fun. Kids can follow ... the guide to build three exciting tracks or design their own. As marbles roll, twist, and race to the finish, kids learn how speed, slope, and direction affect momentum. The snap-in tile system makes building easy and stable for frustration-free play. Along the way, kids strengthen problem-solving, creativity, and early engineering skills through hands-on experimentation. Perfect for curious minds ages 6 and up.