Even younger :) We had some aerated concrete brick left after rebuilding our bathroom and my son (4yo at the time) "crafted" them with tools like saw or nails

Even younger :) We had some aerated concrete brick left after rebuilding our bathroom and my son (4yo at the time) "crafted" them with tools like saw or nails and screws. He really enjoyed that. It stressed a lot his grandfather, to see his grandson with sharp tools, but the boy was very proud of his work.