Teachers set pupils theoretical or practical tasks -- like preventing an ice cube from melting using household items -- to help them develop problem solving skills. In trying to prevent an ice cube from melting, pupils are allowed to use items like cardboard, newspaper and tin foil. Not only is this exercise stimulating, it's also good fun.
Take two bags of frozen vegetables out of the freezer. Place the ice cube on top of one of the bags. Place the other bag on top of the ice cube, so that it is completely surrounded. The ice cube will be prevented from melting, at least for a while.
Try a different approach by wrapping the ice cube in several layers of cling-film. Then wrap it in a tea towel, or several tea towels. This will insulate the ice cube from warm air and slow down the melting process.
Wrap the ice cube in several layers of tin foil to begin a third method. Wrap the tin foil parcel in layers of cotton wool. Place the cotton wool bundle in a tin. Put the tin on a cold tile or stone floor. Heat rises, so placing the tin on the floor -- out of the sun -- will keep the ice cube from melting quickly.
Use felt, newspaper and wool, suggests one source. A combination of all three would be very effective. Wrap the ice cube in a whole newspaper, one sheet at a time. Wrap this in a layer of felt, then wrap the felt in a wool blanket.
Place a tea towel over the ice cube and smash it to pieces with a meat hammer, if you want to approach the problem with some “blue sky thinking.” With all the other methods, melting will take place, although more slowly than normal. This way, the ice cube will never melt because it no longer exists.