This is a fantastic problem that draws from multiple concepts and abilities, yet is entirely approachable. If your students are learning scale factor and conversion between units, this is a fantastic problem. There are notes at the bottom of the slides that will help guide you through the lesson. Please feel free to contact me with comments or concerns at: thebeardedmathman@gmail.comFor other lessons and math topics, please visit: http://thebeardedmathman.com