This post inspired a classroom activity and corresponding reflections. If you would like to see how this went when it was given to a group of young people, please feel free to check out Mathematical Modeling: The Glass is Half-Full.
I was drinking a glass of water recently. The glass looked like this:
Notice how the glass gets wider as the glass gets taller. This will make the task of drawing horizontal half-way line (that is, the line where half the volume of the glass is above the line and have the volume of the glass is below the line) more difficult.
So, how would you figure out where to draw the horizontal half-way line? Would that method work for finding the quarter lines as well?