70 Sparkling Imagination of Your Kids - Marble Race Track This marble race toy is a best! The 70 pcs DIY trace building blocks are a good educational toy for your family. The marble race track is a great item to teach young kids about momentum and properties of gravity through the marble running in the track. You can put them together as you like, so you can let your kids build the blocks differently each time with their imagination. This is a great game for your family.