People learn best when they are seeking the information they need or want. You can "expose" them all day long to a subject, but it will go right past them. The trick for parents and teachers who want to broaden the horizon is to find some way to capture the student's interest. Then, having ignited the fire of curiosity, we can watch with satisfaction as the students take charge of their own learning.
At Saint Columban's, we do everything we can to create a context that makes the children want to know more. From living history, to games, to field trips, many of our activities don't look much like school at all. Most subjects don't take long to teach, as long as the student is ready and eager to learn. As a matter of policy, we spend more time stoking that eagerness and less time pushing information at our kids.
One year, we wanted to do a unit study on ancient civilizations. We read piles of books. We made pyramids and wax tablets. It seemed to sink in pretty well, but not as well as we had hoped.
Then, we got our third-grader a copy of Civilization III, a computer game about ancient civilizations. (Here is our review of it.) It wasn't part of the core curriculum, to be played during working hours; no, it was for weekends. In a way, that made it more tantalizing. It's very playable and enjoyable. After playing this game for a while, our student began to really understand that civilizations rise and fall, that knowledge is cumulative, that cultures compete, and so on. On his own initiative, he dug out a history book and begin poring over it, looking for things that might give him an advantage in the game.
By the time we rented "Ben Hur" and "Cleopatra" from the video store, he knew all about galleys, and legionaries, and the relative merits of steel and bronze weapons. To our way of thinking, this was a home schooling home run! The game may not have taught much history, but it made the student care about history.