We were recently counting our money, when Logi-Bear tried to eat one of the pennies. My main reason to not let him? Because money is dirty. Which naturally led to a discussion about cleaning the money, and started our next experiment!
What is the best way to clean a penny?
We looked up methods of cleaning pennies, and choose 4 relatively easy ones that we had all the materials for.
In the end, the ketchup and baking soda worked the best! It wasn’t difficult at all, and produced a pretty clean penny. The eraser was the simplest, but it was too tedious. The lemon and salt was neat because of the bubbling reaction, but it turned the penny a strange color. And lastly the vinegar and baking soda worked okay, it just didn’t work as well as the ketchup and baking soda.
The boys loved seeing how clean we could get the pennies and which method would work best. We found out that once pennies get that black on them, they’re nearly impossible to clean, so when cleaning your pennies choose ones that aren’t blackened.