In these interactive visualizations, explore the relationship between calculating miles per gallon (mpg) to gallons per mile in fuel use for vehicles. Most drivers think gas usage falls linearly (in a straight line) as mpg increases. But the actual relationship between the two is curved: one additional mpg has significantly greater impact in the gas consumption of an inefficient vehicle than it does in a more efficient vehicle. In the accompanying classroom activity, students will further explore this idea through guiding questions, classroom discussion, and a writing assignment. This resource is part of the Math at the Core: Middle School Collection.