Self- direction is the best direction.

I love it when children create their own programming.  It's one of my favorite parts of my job- when they come up with a topic that I can help them explore.  Just the other day I had brought in a tub of snow for them to play in and had objects for them to use for the snow (like an empty ice tray, a "sifter," shovels, buckets, etc).  One child, while filling up the ice tray, said "we should ask Miss D. to put this in the oven so we can have ice cubes."  I asked them a silly question: "wait, how do we make ice cubes from the snow?"  "You cook it in the oven," he answered, unwavering.  "Is that so?"  By now the rest of the children were listening and had decided that he was probably right- if you "cooked" snow in the oven you would have ice cubes.
So we tried it.  I had them fill a baking pan with snow, and we asked Miss D. to put it in the oven while we ate our lunch.  Minutes later we took it our of the oven- water (as you probably knew).  "Why isn't it ice?" I asked. 
 One little girl piped up- "because it is hot in the oven, so the snow melted."  "
Oh,"  I answered, "so we can't make ice?" 
"Put it in the freezer!" Nearly all of them yelled at once.
So we did, and then they played with the ice it made.
Now, this is not rocket science, but discoveries like this are so important for this age group.  Not to mention, they were so proud of this discovery that they told nearly anyone who would listen that they knew how to make snow into ice. explaining they had to melt the snow first and then put it in the freezer.
Nothing like a little science on the fly.