The kids found the letters and hid them again.
We tried some different ways to find the letters. Sometimes we dug in the paper. Sometimes we took the paper out and sorted through it.
But we always cleaned up the paper, putting all the pieces back in the box.
The kids had a great time with this. They enjoyed it more than I could have predicted. This reminded me that sometimes just a simple activity, one without a lot of extras or high cost items or high tech equipment. Just paper (that would have been trashed anyway), box, and magnet letters. As Sherry and Donna would say, it was irresistible.