Paper airplanes are a fun activity for the young and young at heart, aviation buffs, or crafters. In short, they have potential to appeal to just about everyone! Those in the early stage might like teaching the grandkids different ways to fold them (are being taught by the grandkids). You can reference www.amazingpaperairplanes.com for different patterns. I chose this website because they give examples in pictures and in short video clips, which I think is nice. Those with more moderate dementia may need more hands-on help making the airplanes, but everyone can enjoy making them fly. Once you have a few made, try having distance races or aim for a target like a trash can or a bull’s eye on the wall.
Be sure to ask questions to encourage reminiscence such as asking about when they made paper airplanes in the past, past airplane rides they took, etc.