Puzzle

Does anyone how this works?

http://digicc.com/fido/

Click the boy to flick through the pages after each task.

Nope - But it's very clever - I like stuff like that

I think Mr Briggs would be able to tell us how this works.

It must be when you type in your remaining numbers - some how the pc can work it out from there??? Who's Mr Briggs?

Mr Briggs is a friend of ours who is a maths teacher now . A master of hard sums.

Best not to find out how it's done - would take the mystery & magic away from it

Spoiler ... http://mathforum.org/library/drmath/view/70348.html

mysteryshopper wrote:

Spoiler ... http://mathforum.org/library/drmath/view/70348.html

Thanks for the details. I vaguely remember hearing one of my mathematics (maybe calculus?) professors talking about this at the university but perhaps I was not paying to much attention to that peculiar lesson...

I actually read that Mysteryshopper just after I wrote that last post - good how it's done though - still quite amazing