Such brilliant materials to introduce early math concepts through play and senatorial discovery. My 30 mo. old was immediately drawn to these when I set up a Dino-dig sensory bin for her! She had so much fun digging for “fossils” and comparing their sizes. These bones definitely have some weight to them, so that’s something to keep in mind if you have a child that likes to throw things (my 15 mo. old). Yellow Door also sells a set of match and measure cards to accompany this set, and I think together, these materials would make for amazing math materials for older toddlers!