The materials you need are Borax, pipe cleaners, a wide-mouth jar, a pencil or skewer, string (or yarn), scissors, measuring cup and spoon, and water (and apparently an Angry Birds pig car.)
First, bend your pipe cleaners into whatever shape you want. We did snowflakes, hearts, and shamrocks. Next, cut off a length of string and tie it to your pipe cleaner shape. Tie the other end to the pencil. Place the pipe cleaner shape in the jar with the pencil resting across the mouth of the jar. Make sure no part of the pipe cleaner is touching the sides or bottom of the jar.
Take the pipe cleaner shape out of the jar and make the Borax solution. Measure out how many cups of water are needed to fill the jar. Use a teakettle or a microwave to boil the water. For every cup of water placed in the jar, mix in three tablespoons of Borax. (I used this opportunity to have K do some math.) Have an adult pour the boiling water in the jar and then add the Borax. Stir the solution until the Borax dissolves and hang the pipe cleaner shape back in the jar.
And then wait...
And wait some more. We left ours overnight.
To expand on this project, I had K look closely at the crystals and determine what shape they are. We also talked about how hot water can hold more dissolved Borax than cold, and how the crystals formed only after the water cooled back down. We also made the observation that the crystallized pipe cleaner shapes are much heavier than when we started.
I came across this neat one-sheet on this experiment that offers additional questions to ask your little scientist. It was an easy project to do with items we already had around the house. I hope you get the chance to do it at your home as well.