Children 3 and up can begin early exploration of physics, STEM lessons and architectural design using the Unit Block Marble Run - 40 pc. set. Rubberwood blocks feature drops, bumps and routed paths that allow for multiple building opportunities. 10 double-sided concept cards provide building inspiration for different block arrangements as well as corresponding lessons related to physics theories. Set includes 4 starter acrylic marbles and 36 block pieces scaled to unit block proportions allowing for multiple run path possibilities.