After you pour water in the jar, the penny seems to disappear, but it's still there.
Making simple, quick, and meaningful experiments, only requires TO BE WILLING. I have a couple of simple books for this, one is More Magic Science Tricks, the other one is Prove It!, and I'm sure you all have a book with easy experiments. If not, you can find for sure lots of free websites where to get the ideas from, for me a book works better, it's easier to me to open a book when we are downstairs, the girls look at the pictures and tell me, this one mom!, so that one it is, unless I don't have something for it (which it's rare), in which case I buy it next time at the store.
I believe that living books and an occasional experiment such as this will make the difference in their science background knowledge in the long run. Do you agree?