I helped my (10yr old) daughter with a presentation she had to do for school. Topic was computers in general, not only programming.
I taught her to strip a (prepared) old 386 I had lying around. So during the presentation she took out the memory, disk, cpu etc. explained what they were for and how you needed to tell the computer how to shift bits of info around using a program.
Then she had a little quiz, where the computer parts were the prizes. The kids loved it (and I got rid of a bunch of junk :-) ).