The fastest way to melt an ice cube is to add external heat to the cube. Children can learn about heat transfer and the changing states of matter when melting an ice cube. Before starting the game, allow children to discuss ways to melt ice and what they think the most effective ice melting strategies are. Allow the children to think of items in the classroom that may help with melting the ice. Assemble two sets of materials for the class to use in a race to see which group can melt the ice cube the fastest.
Divide the children into two teams. Give each team one ice cube to melt. The goal of the game is to melt the ice cube the fastest. The children can use any of the materials you assembled to try and melt their cubes. Children can also rub the cubes between their hands to melt the ice.
Place the ice cube inside a small plastic container to hold the ice water as it melts. Unless the children hold the ice in their hands, they should not remove it from the container.
Start a stopwatch and instruct the children to begin. Monitor the children to ensure they do not try anything that could harm themselves or damage the room around them. Stop the watch when the first team melts the ice cube all the way.
Discuss with the children their chosen methods for ice melting. Was the winning team's strategy much better than the other team's? Compare the winning ice cube to the size of the other cube. Were they similar in size? Discuss with the children whether they could have melted the cube any faster using other methods. Did any of the children think to break the ice cube into smaller pieces that would be easier to melt?