1. Fill the large mayonnaise jar with the golf balls or rubber
balls all the way to the top.
Ask this question: Is the mayonnaise jar full?
2. Fill the mayonnaise jar up with the little pebbles or rice and
shake the jar lightly so that the pebbles roll into the open
spaces between the balls.
Ask this question: Is the mayonnaise jar full?
3. Fill the mayonnaise jar up with the sand and shake the jar slightly
so that the sand fills the empty spaces around the golf balls and
pebbles/rice.
Ask this question: Is the mayonnaise jar full?
(The sand has filled up every bit of space left. You ask yourself:
Has it?)
4. Now pour the water into the mayonnaise jar and watch as this
liquid effectively fills the empty space between the sand.
Ask this question: Is the mayonnaise jar full?
Finally the empty mayonnaise jar has been filled completely.