3 years and 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 set (sold separately). The 8" x 11" Activity Cards are made from durable Pvc and are great for outdoor use. Bury the 16-piece Dinosaur Bone set 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.