According to tradition as recorded in the Talmud; at the time of rededication, there was very little oil left that had not been defiled by the Greeks. Oil was needed for the menorah in the Temple, which was supposed to burn throughout the night, every night.
There was only enough oil to burn for one day, yet miraculously, it burned for eight days, the time needed to prepare a fresh supply of oil for the menorah.
An eight day festival was declared to commemorate this miracle. To incorporate this into our week of our Hanukkah festivities, we conducted an oil experiment with oil, water, food coloring, molasses, and honey.
Doing so enabled your little one to acquire new language (words like density, heavy, viscous, cloudy water) as they applied their knowledge of science concepts such as observation, speculation, and implementation.