The Great Backwards Ice Cube Melting Race!

What’s the Point?

  • Some materials act as better insulators than others
  • Insulation keeps energy from transferring from an object to its surroundings. It keeps temperatures from changing and can keep cold objects cold or warm objects warm
  • With good insulation the melting rate of ice can be decreased
  • Earth's atmosphere acts as an insulator to keep our Earth warm


In this optional 15-20 minute activity, teams of children ages 8-13 compete to predict which material acts to best to insulate ice – to keep it from melting. Each team is given their very own racing cube and can choose from a variety of materials to protect it from melting. The winning team will be the one with the largest piece of ice left after 10 minutes of melt time!


For each child

  • 1 popsicle (optional)

For each group of 3 to 4 children

  • 1 small bowl
  • Tape
  • 1 ice cube (racing cube)
  • An insulator for their racing cube, chosen from a variety of materials such as foil, plastic wrap, felt, Styrofoam, newspaper, even containers of water at different temperatures, etc.
  • A Styrofoam ice chest (optional)

For the facilitator:

  • A timer, stopwatch, or watch with a second hand
  • Background information


  • Precut a variety of insulation materials into 5" x 5" squares
  • Place your ice cubes where they are readily available, preferably in a Styrofoam chest
  • In a convenient location, place several types of ice insulators from which the children may choose
  • Be prepared to discuss what they have learned in their Ice Investigations!


1. Divide the children into teams of 6-8. Explain that in a moment they will begin The Great Backwards Ice Cube Melting Race. First, however, ask them if they have ever heard of insulation.

  • What is insulation? Some children may say it is a material that is used in attics or walls. And that is true! Insulation is a special material that prevents or reduces the passage of heat. So in the winter, it is used in houses to prevent the heat escaping.
  • Can they think of a way they personally use insulation? When they go outside in the winter, they wear jackets and sweaters to keep their body heat from escaping.
  • Do they ever use insulation to keep something cold? Absolutely! In the summer they use a Styrofoam ice chest to insulate their drinks and keep the cold in and the heat out! And some of them may even use a thermos that keeps hot drinks hot and cold drinks cold! How does that work? Tell them you will discuss that with them after the race!

2. Explain to the children that, as a team, they will receive one racing (ice) cube and will be given a choice of materials to insulate it. Tell them that the name of this race is The Great Backwards Ice Cube Melting Race because the object of the race is to have the cube that melts the slowest! Their task is to decide which material will insulate their ice cube the best and keep it from melting!

3. Before issuing their ice cubes, allow the children to examine the materials and choose the one they think will insulate their racing cube the best. While they are choosing their material, you may distribute the bowls and tape to each team. Encourage each team to choose a different material, if possible.

4. After each team has chosen their insulating materials and regrouped, distribute a racing cube to each team. You may let them choose their own and, just for fun, they can even name it! Encourage them to wrap their cube as quickly as possible and use the tape, if necessary, to secure the material.

5. Share with the children that the race will last 10 minutes. While their ice cubes are racing, have each team record on poster paper and share with the larger group the reason(s) why they chose the particular material they did, and what they have learned so far about ice!

6. After 10 minutes, tell the children it is time to reveal the winner of The Great Backwards Ice Cube Melting Race! Have the teams unwrap their cubes and display them in a common area. You may have to examine them closely to determine a winner, as some of the materials - like felt and newspaper - are both good insulators. If two or more teams choose the same material, there may be some ties. There should be quite a difference between the cubes that were wrapped in felt or newspaper, for instance, and those wrapped in foil.

7. After the winner(s) are announced, ask the children if they remember the question about the thermos that keeps cold things cold and hot things hot. Explain to the children that good insulation keeps both heat and cold from escaping or penetrating! That is why insulation in your attic keeps the cool air conditioning from escaping, while at the same time keeping the hot air outside from getting in. So, a good insulating material - like the felt - did not let the warmer outside air get to your cube, and it kept the cool air from your cube from escaping. The same principle applies to your jacket in the winter. The jacket keeps the cold outside air from getting in, and it keeps the heat from your body from getting out (So yes, you should listen to your mother when she tells you to put on a coat!).

8. Encourage the children to extend their thinking! Now that the children have an understanding of how insulation functions, ask them to apply that to our atmosphere and Earth by thinking about a few ideas:

    • Earth’s temperatures range from 58° C (136° F) to -89° C (-129° F).  On a summer day where you live, when the Sun is shining, the temperature might be as warm as 27° C (80° F) or 32° C (90° F). At night the temperatures may cool to 21° C (70° F). And yet, space is about 270° C below zero ( -450°F) – much colder than Earth.So if Earth is located in space, and space is really cold, what keeps our planet from freezing?
    • The temperatures on the Moon range from 117°C (243°F) on its sunny side to --169°C (272°F) when it is nighttime on its far side. The Moon does not have an atmosphere.
    • So what does the Earth have to keep warm? Could it be that Earth has some kind of insulation? Yes! Our atmosphere is what keeps Earth warm in the cold, cold space - just like your jacket or a blanket does for you in the winter.
    • Where does our heat come from? Two places – the Sun and the Earth. Our Earth is warm inside and creates heat; evidence of this (geothermal) heat can be seen in Earth’s volcanos and hot springs. The Sun’s radiation that reaches Earth’s surface warms the land and water. This radiation is re-emitted and is trapped by our atmosphere. This trapping of heat keeps Earth’s temperatures relatively warm and stable.
    • What do you think would happen if you had on five jackets or blankets? The children will probably say they would get "too" hot!
    • What do they think might happen to the ice on Earth if our atmospheric blanket got thicker – or made of a material that trapped more heat? Allow the children to share their thoughts about this. Accept all answers at this point, and tell the children that they will be investigating this further later.

In Conclusion

Once they have completed the activity, invite the children to revisit their Ice Cube and to record any answers they discovered on the appropriate side of their Cube. Have them annotate any new questions they have or interesting things they learned on the raindrop, cloud, and snowflake templates.