This is a revisited summer project for us. The boys were able to do a lot of it alone this year. First we filled up a tub & a cake Pam with water. Then the boys ran off in search of little trinkets & toys. Meanwhile, for fun I dug out some treasure... Coins. We dumped all our booty into the water & put the pans in the freezer.
While I had my coffee on the front porch first thing next morning, the boys ran in to get their ice-treasure. The ice cubes quickly slipped out I the bowls and the boys went at the ice cubes. I let them use table knives. I think we have used spoons in the past.
This year, of course, the boys got the treasure out & spent the rest of the time tossed the ice up & watched it shatter on the concrete. ☺