While talking about the metric system with my class, I wanted to see if they could figure out what cent- means as well as how many centimeters were in one meter.
"How many cents in a dollar?"
"What do you color to for your percentage?"
"How many years are in a century?"
"How many centimeters are in one meter?"
"What does cent- mean?"
"I know," says one of my catch-it-all students. "Coins!"
Ugh, as I smacked my forehead.