NASA's Smart Skies™ features an interactive Air Traffic Control Simulator that enables students to apply proportional reasoning to make decisions and resolve conflicts in realistic air traffic control problems involving two or more planes. "Line Up With Math" is an introduction to the module for student in grades 5 through 9, where students are challenged to line up the planes safely, with proper spacing, on time, at a given intersection of jet routes. For more information about the Smart Skies™ program, please visit http://www.smartskies.nasa.gov