■ Working time: 20 minutes
■ Material cost: About $4
·Liquid food coloring
· Ziplock bag
· Vials or test tubes
1. In a ziplock bag, put a small amount of rock salt and pour a few drops of food coloring on. (The amount is up to you) Close the mouth of the bag and shake to make the color blend throughout.
2. Color salt and granulated sugar in the same way as 1. Prepare 3 to 4 colors.
3. Using a spoon, put colored rock salt in the vial. Put in colored salt and sugar in layers until it is full. Gently even out by knocking against the desk.
4. Close the lid of the small bottle so that the contents do not come out. Done!!