While summer does not officially start until June twenty first, with many schools out and the temperatures climbing it feels a lot like summer well before then. This is a great activity for a hot day. It is fun to mix a little science and math with home made ice cream. Measurement is a mathematical skill. Make sure you give your child the opportunity to measure out the ingredients. You can explain that the reason we add salt to the ice is that it lowers the freezing point of water.
Here is a link to a more thorough explanation of the science behind this experiment:
http://science.howstuffworks.com/nature/climate-weather/atmospheric/road-salt.htm
Materials:
2 sandwich size ziploc bags
2 gallon sized ziplocs
1/2 cup of half and half
1 tablespoon sugar
1/2 teaspoon vanilla
ice
1/2 cup rock salt (sodium chloride NaCl)
winter gloves
Directions:
1. In one of the sandwich bags mix the half and half, sugar, and vanilla. Seal the sandwich bag. Then place the sandwich bag in the second sandwich bag and seal.
2. Place the sandwich bag in the gallon sized bag and fill with a mixture of ice and rock salt. Seal the Gallon sized bag and place in the second gallon sized bag and seal.
3. Shake the bag until the ice cream hardens.
4. Enjoy!
