Lightspeed? Oh yes, you can show kids that they have 11 fingers!

First grade kid is best.

me:
lets count your fingers. You don't mind if we count up or down?
does it matter?

kid:
no

me:
grabbing one hand of the kid
'OK, let's start. (countings slowly) 10, 9, 8, 7, 6'
'you said, doesn't matter counting up or down?'

kid:
no, does n't matter

me:
ok, let's continue, where did we stop, yeah 6,
(grabbing other hand) hmmm, let's count up now!
(counting fast) 7,8,9,10, 11 - oops, you got 11 fingers?

....faster than speed of light!

73's de Wolfgang OE1MWW