If you're looking to pass the time with your kids and want to feel like scientists in the kitchen, might we suggest making some soap jelly? Alternatively, if you're looking to add some new cleaning supplies to your cupboard, soap jelly can clean everything from marks on the walls to stains on your kitchen counters. You only need a bar of soap and some water to make this a reality, too.
Simply grate a bar of soap into a pot, fill the rest with hot water, and let it cool overnight. By the time you wake up in the morning, it should have turned into a jelly.