This Instructional Activity is a part of the Lesson 8, Unit 1, Grade 7. Write an equation that will model the real-world situation. Example 1: Do We Have Enough Gas to Make It to the Gas Station? Your mother has accelerated onto the interstate beginning a long road trip, and you notice that the low fuel light is on, indicating that there is a half a gallon left in the gas tank. The nearest gas station is miles away.