I am constantly amazed by the things that kids are capable of, if we only give them the chance.
In preparation for Thanksgiving, I had a whole pot full of hard-boiled eggs that needed to be shelled. I asked Secundus to help and taught her how to do it. Of course Tertius wanted to get in on it, too. So I handed him one that had cracked while it was boiling so I wasn't worried about him ruining it because it was already ugly.
They both did great! Both of them went on to shell several eggs for me and Tertius only ruined one! In fact, I think some of the ones that Secundus shelled looked prettier than the ones I did.