Example:
2 identical boxes on one side of a scale equally balance a 9 ounce box on the other side. How heavy are the 2 boxes?
Common sense says the boxes are 4.5 ounces each, but my son answered that, and got it wrong.
What kind of wacky algebra-give-a-letter-for-an-answer-even-though-letters-arent-math-answers problem is this?