I suggest showing them some simple programs in Scratch (http://scratch.mit.edu). It's like turtle, but with a block programming interface, and a built-in graphics editor. You could bring in a computer with a projector to show them basic commands and what the commands do. Kids that age are able to understand it, and have fun making a simple animation or game. Our elementary school has a computer lab; if yours does you could bring the kids there after your demonstration for some hands-on work. If there isn't a room with a lot of computers, you may be able to ask a few parents to bring in laptops so that the kids can try it.
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I suggest showing them some simple programs in Scratch (http://scratch.mit.edu). It's like turtle, but with a block programming interface, and a built-in graphics editor. You could bring in a computer with a projector to show them basic commands and what the commands do. Kids that age are able to understand it, and have fun making a simple animation or game. Our elementary school has a computer lab; if yours does you could bring the kids there after your demonstration for some hands-on work. If there isn't a room with a lot of computers, you may be able to ask a few parents to bring in laptops so that the kids can try it.