The idea is to use food coloring to dye water. Pour that water in a large pan (I used a 9x13 metal baking dish) and then place toys in the water. Put the pan in the freezer overnight until it freezes into a solid block. Our pan of ice popped right out the next morning without needing any encouragement (ie. warm water) to help loosen it.
Place the ice block outside & let your kids "have at it." Depending on the age of your little one - the fun & learning begins. We gave Jonah his toy tool set & a watering can to help him problem solve around how to free the toys from their icy grip. Jonah is 3 years old, so although the learning & experimenting is rather limited, the fun is big-time.
For Jonah, he had fun feeling the smooth texture of the ice, the coolness and how "stuck" the toys were. He also liked seeing how shiny & wet the ice became when water was poured over top. At one point, toys could be pushed all the way through the ice leaving a hole where fingers could wiggle in the window left behind; he thought that was funny. Jonah used a variety of toy tools with varying degrees of success. Eventually, however; he discovered through help of a "big brother" that if you stand up and drop the ice, it breaks - thus, freeing lots of toys at once. Fun!
And, of course, eating the shattered pieces of ice was his favorite part of this activity.