After eating a lot of avocado and guacomole, we decided to have a crack at sprouting some of the avocado seeds. According to the instructions the bigs looked up, we needed two skewer the seeds on toothpicks and suspend them in water for 6-8 weeks or something to that effect.
10yo found an experiment on Youtbe that she wanted to try, which involved dropping hot water into cold water rapidly to see if they mixed. So we would be able to see if there was any mixing going on, she colour coded the water with food colouring after boiling the hot water.