What is a mastery project? I use mastery projects for every standard in math. This is an option I have for students to show they have mastered a standard by using a skill in a real world scenario!
This mastery project allows students to use their ability to master elapsed time to choose the shortest flight for a weekend vacation. I use this as a post-test, to show that they have mastered the skill. It could be used in stations, as a must do, or even as a whole group math talk!