On Mon, 7 Jan 2013 14:02:52 +0000 (UTC), D.M.Chapman wrote:

... but that's two 11 year olds who spent several hours listening to
science instead of playing minecraft.

Ah Minecraft, big time sink if there vere was one but at least there is
the opertuneity to "build" stuff and use the imagination, rather than sat
gorping at the idiots lantern.

My lad (12) has "built" the basics of an 8 bit computer using the
Computercraft plugin for Minecraft. Needed a bit of help finding the
logic diagrams of binary adders and a general description of how you use
registers to store numbers but build it he did and it works at least to
enter and add two 8 bit numbers.

Just because there isn't a physical "product" doesn't mean they aren't
"building" things...

--
Cheers
Dave.