View full lesson: http://ed.ted.com/lessons/how-to-defeat-a-dragon-with-math-garth-sundem Having trouble remembering the order of operations? Let's raise the stakes a little bit. What if the future of your (theoretical) kingdom depended on it? Garth Sundem creates a world in which PEMDAS is the hero but only heroic when in the proper order. Lesson by Garth Sundem, animation by Mark Phillips.