Sal is looking at a map of Massachusetts. He has measured the distance, in inches, from Boston to Salem on the map. He wants to know how many actual miles the inches represent. What feature of the map should he look for?

The questions have been asked in several important state and regional science exams in the United States. For example: TAKS-Texas Assessment of Knowledge and Skills, New York State Educational Department Regents exams, California Standards Test, etc.