

Finger binary - lobo_tuerto
https://en.wikipedia.org/wiki/Finger_binary

======
Whitespace
I love to teach finger binary to kids but they always start giggling when I
hit 4 and they never really ignore it :(

~~~
JTxt
Ha! I find that I can tap my fingers on a surface easier than pulling fingers
down in many of those combinations. Perhaps it would be less distracting if
they saw you just lowering the middle finger onto a table?

------
socialist_coder
My friend and I tried to use this method while scuba diving to communicate how
much air we had left. It seems perfect- 1 quick flash of 5 fingers can display
any number between 0 and 31, which in this system would be 0 to 3100 PSI.

(Scuba air in the US is measured in PSI and scuba tanks cap out at 4500 PSI,
and since you never care about accurately communicating your air level unless
its down past 50% or so, the upper limit of 3100 is sufficient)

Unfortunately, since thinking in binary doesn't come naturally to us, we would
have to convert the binary into decimal in our head, which is difficult, error
prone, and ultimately more work than just using one of the tried and true
methods for communicating how much air you have left. We went back to the
normal way after a few dives.

I think with practice though it could work.

~~~
doughj3
What kind of tanks were you diving with at 4500psi? I worked for a scuba shop
for a couple years and we never did even a hot fill past 3400 on an aluminum
tank, never mind steel tanks.

~~~
socialist_coder
You're right, I'm mistaken. 3400 PSI on our high pressure steel tanks. You can
tell it's been a while since we dove a lot =P

------
kshep
You can also go pseudo-base-5, which will get you 99 and it's relatively easy
to know where you are: right hand fingers are 1s, right hand thumb is 5, left
hand fingers are 10s, left hand thumb is 50. Edit: Someone in another comment
points out this is just Chisanbop:
[http://en.wikipedia.org/wiki/Chisanbop](http://en.wikipedia.org/wiki/Chisanbop)

------
mattr555
ViHart did a video on this:
[https://www.youtube.com/watch?v=OCYZTg3jahU](https://www.youtube.com/watch?v=OCYZTg3jahU)

------
dunham
When I first tried this, years ago, I found it too awkward. I eventually
settled on using my thumbs for five, and my fingers for single digits (like a
Japanese abacus).

This feels reasonably comfortable to me, is easy to use, and covers a
sufficient range of numbers for my needs.

~~~
gojomo
Sounds like Chisanbop/Fingermath:

[https://en.wikipedia.org/wiki/Chisanbop](https://en.wikipedia.org/wiki/Chisanbop)

~~~
dunham
Yeah, pretty much identical, except there is no table involved. Thanks for the
link.

------
memset
There is another trick, which yields 12 digits per hand.

Using your thumb, tap each of the 3 joints of your fingers as you count,
starting from the base. Go from your index finger to the pinky. If you need
more, just wrap around and continue counting.

~~~
Theodores
[http://en.wikipedia.org/wiki/Sexagesimal](http://en.wikipedia.org/wiki/Sexagesimal)

It explains why 12 and 60 are such important numbers for measuring time and
angles, amongst other things.

------
sesteel
This is how I taught my daughter binary when she was 6 years old. It stuck
with her and is the one thing I taught her that I can point to as giving her
confidence in math. When I was satisfied with her retainment, I bought her one
of those, "There are 10 kind of people..." shirts. She still wears it.

She has yet to figure out why my wife and I laugh when she gets to 4.

~~~
aestra
In primary school my mom told me she learned different bases of numbers in
math. She said her dad kept saying "who would ever need this!"

~~~
sesteel
That is awesome. I feel that kids today are expected to be successful but not
really learn; at least here the US. Though, in my daughter's school they are
learning simple circuits in the 4th grade.

------
mhaymo
Brings new meaning to the word "digital". I'll be here all night.

~~~
Nav_Panel
I mean, that is the origin of the word "digital":

>1650s, "pertaining to fingers," from Latin digitalis, from digitus (see
digit). Meaning "using numerical digits" is from 1938, especially of computers
after c.1945; in reference to recording or broadcasting, from 1960.

Source:
[http://www.etymonline.com/index.php?term=digital](http://www.etymonline.com/index.php?term=digital)

------
augustocallejas
On my college freshman orientation sheet, I put down counting binary by finger
as something "interesting" I knew. Afterwards , I felt silly but now that
there is a dedicated Wikipedia page, I feel better.

------
clord
Using whole fingers for binary is more useful on a table or when trying to
remember numbers.

On the go, I find myself using the finger-bone counting method, where you use
your thumb to point to each of your finger bones (3 per finger) allowing you
to count 12 on a hand. This probably has a name since it's so easy. And 12 has
lots of really nice factors when doing math on the go.

If you point at the joints plus the tip of each finger, you have 4 positions
per finger (i.e., nibbles), which can be useful for working through power-of-2
stuff.

~~~
mkesper
This has a reference to how I got taught which months have 31 days: knuckles
(31) vs space between knuckles (30/28) days. As between July and August you
have to skip hands, that's the only two months in succession with 31 days.

------
walrus
Cute:

    
    
      It is possible to use anatomical digits to represent numerical digits[...]
    

Also, 8 and 23 are really difficult for me (and the left hand equivalents).

------
shubhamjain
This thing makes me so nostalgic. There was a "magic" which we kids used to
play with others in primary.

We created a list of 15 random items, and asked one to pick anyone of it.
After which we asked the volunteer to tell which of the four sublists has the
item. When this was done, we proudly told him / her what was it and it
literally left them clueless how we did it, until of course, the trick went
viral and everyone was doing it with others.

~~~
Ellipsis753
I don't think I understand the trick. Could you explain it more? It sounds
very interesting...

------
coldtea
An idea I had -- perhaps it's been already thought by lots of people:

Use the binary system to give access to tons (well, at least 128 or 256) notes
to a musical instrument design.

You just need like 8 buttons (compared to over a dozen for a flute or 88 for a
piano), so you can make it quite compact.

I'm thinking of some digital controller like instrument, but if they could
pull off an analog one, that would be interesting too.

~~~
mkingston
I'm _far_ from a musical expert, but I thought this was essentially how many
instruments work: Each string/hole/whatever produces a different resonant
frequency which is orthogonal from the others the instrument produces;
therefore any combination of strings/holes/whatevers creates a sound that
cannot be created by any other combination of strings/holes/whatevers.

Please, correct me if I'm wrong.

Edit (before someone nitpicks, I'll do it!): I'm aware interacting with
instruments doesn't produce _only_ resonant frequencies; and that the off-
resonance is what gives an instrument its characteristic sound, even when
playing the same note as a different instrument.

~~~
iansinke
That is exactly correct, for wind instruments at least: and in fact, some wind
instruments have more than 10 holes or keys. But many combinations produce
identical sounds, limiting the range of the instrument. The limiting factor on
a wind instrument is the fact that it can only play a single note, (yes, with
resonant frequencies, of course) and the length of the instrument, which
determines the lowest note it can play.

~~~
mkingston
Thanks for that. A little more to slow burn in my understanding of instruments
before I eventually learn one!

------
RBerenguel
You can also half-bend fingers and use base 3, getting up to 59048, even
though some numbers are somewhat complex to "form"

------
deletes
Range of 1023 versus 10 for decimal. I like it.

The number 132 is pretty unfortunate. Showing it might cause miscommunication.

~~~
killercup
"Normal" counting is _unary_ (base 1, amount of fingers shown = number
represented). Decimal would mean 10 states for each finger.

~~~
deletes
It can be whatever you want it. 10 states for two hands. Or take 8 fingers and
you get a byte.

~~~
frou_dh
If it were decimal you'd be able to show us 6552920451 using your ||||||||||

------
simgidacav
Hopefully nobody will be offended by 4.

------
jere
Curiously, the example photos don't demonstrate the obvious values of 4, 128,
or 132.
[http://en.wikipedia.org/wiki/Finger_(gesture)](http://en.wikipedia.org/wiki/Finger_\(gesture\))

~~~
lobo_tuerto
Oh, someone already addressed this:
[https://news.ycombinator.com/item?id=6863804](https://news.ycombinator.com/item?id=6863804)
;)

------
lifthrasiir
Reminds me of a finger binary ASCII art generator for Python:
[https://gist.github.com/sublee/600592](https://gist.github.com/sublee/600592)

------
doctoboggan
My dad taught me how to count like this when I was a child. Only he taught me
to use my thumb as the 16 place, which makes it easier to count quickly in my
opinion.

------
ratsimihah
Cool, I was looking for a system to implement Ender's Game's 5-fingers
keyboard. ASCII to hex to binary to finger binary!

~~~
SimHacker
I think Doug Engelbart deserves credit for introducing the chord keyboard,
which he demonstrated in "The Mother of All Demos", not a fictional book
written by that homophobic anti-American bigoted foaming at the mouth lunatic
Mormon cult member who sits on the board of directors of the National
Organization for Marriage.
[https://en.wikipedia.org/wiki/Chorded_keyboard](https://en.wikipedia.org/wiki/Chorded_keyboard)
[http://www.youtube.com/watch?v=JfIgzSoTMOs](http://www.youtube.com/watch?v=JfIgzSoTMOs)
[http://americablog.com/2009/04/mormon-leader-of-nom-
appears-...](http://americablog.com/2009/04/mormon-leader-of-nom-appears-to-
advocate-overthrow-of-us-government-by-whatever-means-necessary-and-
criminalization-of-homosexuality.html)

I own an original Enbelbart chord keyboard and mouse set. It was given to me
by a friend who worked at SRI, who maintained Doug's PDP-10 that he used to
give demos of his work. Some day I hope to hook them up to an Arduino, so I
can use them on a more portable computer that a PDP-10!

------
killercup
I've been meaning to make a habit of counting this way, but it's quite rare
that I count using my fingers at all.

------
Xophmeister
I could cycle through all 1023 combinations in under six minutes when I was
17... Hmm... Misspent youth!

------
thunderbong
How come Wikipedia doesn't show how to do 4?

