These worked as (terrible) eraser replacements, in a pinch, though the knowledge of why so many of us had these when we didn't have an eraser has been lost to the ages.
My dad used to drive us to a long stretch of road, speed up, and toss these out the window in front of the car so we could watch the bounce at high speed.
In hindsight not good for the environment, but it was fun
Mmmm crumbly rubber
These worked as (terrible) eraser replacements, in a pinch, though the knowledge of why so many of us had these when we didn't have an eraser has been lost to the ages.