An ounce of cola

Which is more expensive; gasoline? milk? or cola?  Students calculate the per ounce cost of each of these liquids in a story about a man doing errands.  After finding the per ounce price, students find costs of gasoline, milk and cola when presented in the metric system.  Which was easier or more efficient, comparing quantities in metric or in U.S. units?  Interesting discoveries and discussion should ensue.

Thanks to Joe Laskowski, a 6th grade math teacher from Bloomfield, CT, sent us this great unit pricing activity.  Also, thanks to Sniff Programming for the idea of incorporating in the U.S. units versus metric units portion of the task.