Ugh! Typed out a huge answer and lost it...
Depends on your subject.
For Science, we have:
* Used celery and food coloring the determine the xylem in plants.
* Planted a terrarium as a "final" on the plant unit, including having the kid find a good place to put it and care for the plants for a few months.
* Built a weather station and recorded the weather for two weeks (rain gauge made of an old soda bottle, anemometer of straws and paper cups, etc.)
* Moved a heavy book across the kitchen floor using pencils as rollers (simple machines)
* Rigged ropes and pulleys to lift a 50-pound bag of salt to the top of the jungle gym
* Taken classes at the local science museum
* Gone to the zoo (animal classification) with things like feathers (challenge the kids to get them wet in the fountain) and empty eggshells (bird vs. reptile eggs)
* Watched a metric ton of Bill Nye videos (Bill! Bill! Bill! Bill!)
Older teens might do things like gather data for a grad student a the local university, or spearhead a volunteer effort to restore a wetlands or prairie area.
For Math we have:
* Used dominoes (adding, subtracting, matching, etc.)
* Used a deck of cards (games of "war," including taking two cards at once and adding or multiplying them)
* Used dice (same as the cards)
* Used Khan Academy online videos and exercises (free)
* Used pattern blocks (patterns, tessellations, geometry, etc.)
* Used counting chips, connecting cubes, ones cubes and tens rods, and geometric wooden shapes
* Played games...so many! (Math Marks the Spot, Dinosaur Math Tracks, Auntie Pasta's Fractions, Presto-Change-O, etc.)
* Used iPhone Apps (MathDice, Sodoku, Cute Math, Squeebles, PopMath, Multiples, Math Ninja, Cyberchase, etc.)
For History, we have:
Really, really relied on the K12 program. We usually do the module, the kids narrate what they learned, and I look for video clips that relate to the subject. A lot of History Channel stuff is out there, like for the Battle of Thermopylae or Pompeii / Mt. Vesuvius.
For English / Writing / Reading we have:
* Used a combination of
- Bravewriter.com
- Barton Reading
* Checked out stacks and stacks and stacks of books from the library. The kids get read to daily, and they read their own books daily. Third grade hits: The Hobbit, Redwall, Harry Potter series, Percy Jackson series, Chronicles of Narnia series. Read on his own: The Wimpy Kid series, Encyclopedia Brown series, every Pokemon book and comic in the library system, and at least two non-fiction book each week. First grade hits: The Boxcar Children, The Hundred Dresses, In Grandma's Attic, as well as H.P. and P. Jackson.
We also look for computer games on those topics I think the kids need help with. For instance, for punctuation:
Punctuation Pyramid:
http://www.primaryresources.co.uk/english/flash/Punctuation%20Pyramid.html
Alien punctuation
http://www.bbc.co.uk/schools/ks1bitesize/literacy/punctuation/fs.shtml
Ship Adventure:
http://www.tvokids.com/games/bigescape3
Comma Chameleon:
http://www.sheppardsoftware.com/grammar/punctuation.htm
Dragon game, find the questions:
http://www.bbc.co.uk/schools/magickey/adventures/dragon_game.shtml