Dave Land wrote:
>
> Julia, et al,
>
> > Describe how to count up to 1023 on 10 fingers. :)
>
> That's easy to describe, but a whole lot more difficult to use :-).
>
> I remember seeing Doug Engelbart (inventor of the computer mouse, etc)
> <http://tinyurl.com/9km7> using a one-handed chorded keyboard
> <http://tinyurl.com/3ajld> that worked like your suggestion. Imagine
> having to learn the binary representation of ASCII characters and repeat
> it reliably! He claimed that it only took a couple of hours to learn.
> But then again, he was Doug Engelbart.
Sounds like something I might like to play with one day.
> Towards the more day-to-day end of the scale, I learned a very usable
> way to count to 100 on two hands. It's interesting in that it mixes
> bases 5 and 10 to work its magic.
>
> Poise your hands just above a surface, as over a piano keyboard.
>
> In this position, your hands represent that famous Arabic contribution
> to mathematics, the invaluable zero.
>
> Starting with your pinky and moving towards your index finger, count off
> 1-2-3-4 by lowering each successive finger to the surface (and keeping
> it there), as you might when drumming your fingers.
>
> Next, lift all four fingers and drop your thumb for 5.
>
> Repeat steps 1-2-3-4 (with your thumb down) to represent 6-7-8-9.
>
> Here's where base 10 comes in.
>
> Raise all five fingers and drop your other pinky to represent 10.
>
> Repeat as necessary. I think you can take it from there.
>
> It's really fast -- I've used it when I had to "count noses" of people
> coming into a room.
I go index to pinky, not pinky to index. Otherwise, this is the system
I've used for counting on my fingers for awhile.
I read an article about it when I was in 6th grade or so. (Maybe 7th.)
It's useful for keeping track of a total when you're adding a lot of
smallish numbers. (The last time I used it was to count the number of
great-grandchildren my mother-in-law's parents have. Not that either of
them are still alive, but it tells me how many people from that branch
are in my children's generation.)
Julia
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