More uses for rubber bands.

Or they could just tear part of it and unroll that way!
Solution: close door
Alternate: beat child and/or pet (I kid!)

I can't see this very practical when you want that toilet paper fast.

Just smash the roll slightly- so it isn't a smooth cylinder. It won't spin. I have seen this trick used in public restrooms.

You could also cheat. Never did it myself; interestingly enough, I saw it back in high-school when they were showing an anti-cheating video.

All you have to do is stretch the rubber band, write the answers on it while it is stretched, and when you are done, just let go. It will look like a simple design/scribbles when it isn't stretched, so a teacher who doesn't know better apparently doesn't notice that you are stretching a rubber band every 2 seconds in a test.

Elastrator Method
This method involves cutting off the blood supply to the testes with a heavy rubber band or ring. In 10 to 14 days, the scrotum and testes will slough off. This method is most effective for young animals whose scrotal tissues have not yet become well developed. Materials needed include an elastrator (instrument used to apply the bands) and castrating bands or rings (Purchase these from a livestock supply company. Do not use household rubber bands!). It is not necessary to disinfect the elastrator or rings since this method is bloodless.

1. Restrain the animal as described previously.
2. Place a rubber ring on the prongs of the elastrator. Turn the elastrator so that the prongs face the kid's body. Expand the ring by squeezing the elastrator and place over the scrotum and testes. Position it as close to the kid's body as possible without interfering with the rudimentary teats.

3. Manipulate the scrotum until you are certain that both testes are descended below the ring.

4. Press the trigger lever, displacing the ring from the prongs, thereby positioning the ring. Note: Be sure that both testes are below the ring! If they are not, cut the ring and start over.

5. Administer an injection of tetanus antitoxin. Even though this is a bloodless procedure, the tetanus organism can gain entry through the irritated tissue around the rubber ring.

From http://www.goatworld.com/
Yep goat world...