Students have a difficult time understanding force, especially when dealing with a moving object. Many forces can be acting on an object at the same time, causing it to stay in one place or move. By directly observing these forces, students can better understand the effect these forces have on an object. With a simple, student-built device called a Fin-di ("fin dee"), students can visually see the sum of all these forces, called the "resulting force" or "net force." This activity is for upper elementary grades, but could be initiated at lower elementary grades as a visual indication of which way pushing, pulling, rotating, and stopping (friction) net forces are acting on an object. (Contains 6 figures.)