Pour a pint of water into a pan and carefully bring it to a boil. Under your close supervision, ask your child to measure out half a pint of sugar and add this to the boiling water.
Stir the mixture carefully until the sugar dissolved into the water. Pour the solution into a clear glass container.
Ask your child to drop a few drops of food coloring into the solution. This will dye the crystals when they form.
Ask your child to tie a piece of thread around a pencil so that the thread hangs down below the pencil. Attach a paperclip onto the bottom of the thread to weight it down and keep it straight in the jar.
Rest a pencil on the top of the glass container so a portion of the hanging thread is submerged in the solution. Make sure the paperclip is holding the thread straight in the jar.
Ask your child to check the progress of the crystals daily. He will notice they have grown considerably after a few days. Because the crystals have been made with clean water, table sugar and food coloring, they are safe to be eaten.
Repeat the experiment with different food dyes. This will create different colored crystals.