I put out an science exploration today and was impressed that it kept the entire class engaged, talking, touching, exploring and questioning for a solid half hour. That is rare for the attention span of a three year old, let alone all eight! I presented each child with their own tray of table salt, rock salt, water, a pipette, a spoon and a block of blue ice with "monster" eyes frozen inside. Their challenge was to melt their monsters with the materials provided and free the eyes. We discussed how the salt and water would help the ice block melt faster. Then they were free to try it out on their own. They could have unlimited supplies and use them any way they saw fit.
"I put my spoon in and I think it helps the ice melt."
"Look at me, I'm going to dump the water on it and see what happens."
"I can mix the salt in the water."
"I got one, two... one of the eyes came out!"
"I need more water and salt."
"It is fun to make a mess!"
"What happens if you put the ice in the salt?"
"How long does it take to melt ice?"
"See, if I put salt here it makes like a tunnel in the ice."