3 years & up. These exciting Activity Cards are an ideal way to encourage children to match, count, compare, order and measure the bones they discover in the Dinosaur Bones setsold separately. The 8" x 11" Activity Cards are made from durable PVC and can be used outdoors. The 16-piece Dinosaur Bone set can be buried in the sand, soil, or water, and they will appeal to children's instincts to explore, investigate, sort, compare and measure. Buy separately or as a set.