The first thing on Rue’s mind when she wakes up is food. After that need has been taken care of, it’s not unusual for the next question out of her mouth to be if she can do a science experiment.
It’s one of the many things I love about her.
We’ve also been talking about money quite a bit lately–the difference between the coins and bills, parts to whole, save versus spend, that kind of thing. Saving is everything to Rue. She’s one of the only kids I know who, after watching that pivotal scene in Mary Poppins where the bankers try to take young Michael Banks’ tuppence, insists that it’s a better idea to save your money in the bank than feed the pigeons.
Those pigeons won’t be getting any handouts from this young capitalist.
Thanks to Chickadee Magazine for supplying a science experiment that I am functional enough to do just after the clock has struck six in the morning.
Mix 1 teaspoon of salt into 1/4 cup of white vinegar. Stir until the salt is completely dissolved.
Add some grimy pennies. Let them sit for a couple of minutes. 
Why do most of them suddenly look brand-spanking new? Rue wanted to add a dime and a quarter to see if anything happened to them, and who was I to say No? That gave us lots to talk about.
The science is simple enough that even I can grasp it. Pennies contain copper. Over time, the copper reacts with air and forms copper oxide, swathing Mr. Lincoln’s face in a dull, greenish residue. The acid in the vinegar-salt mixture dissolves the copper oxide and restores the shine to the penny.
Whew! Is that you, vinegar???
We noticed that not all of our pennies looked like they’d been through a car wash after a good soak in the vinegar solution. Nacho Man, who loves to talk about the devaluation of currency, would be happy to go on and on and on about how recently minted pennies contain almost no copper at all.
I dare him to.
If I have to listen to it, then so should you.
The Adventures of Pho Girl and Nacho Man 