
Roman Finger Counting - JNRowe
https://tookmund.com/2020/05/roman-finger-counting
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modo_
Cool! I've noticed a similar way of counting that's still quite common today
in China. They point with their thumb to each segment of their four fingers to
count up to 12 on one hand. The other hand tracks the number of 12 counts,
which lets you keep track all the way up to 144 with both hands.

Not quite on the level of the Romans, but still a solid improvement over how
I've done it my whole life!

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dc443
And the Babylonians, whose base-60 system's legacy lives on in our
timekeeping, used the finger segments on one hand and entire fingers on the
2nd hand to count to 60.

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greggman3
Which arguably suggests we didn't settle on base 10 because we have 10 finger
as seems to be often told. We settled on base 10 likely because of politics
(in the broader sense of the word)

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npunt
I imagine there's a natural gravitational pull toward base 10 from having
fingers, and throughout prehistory and early civilization occasionally systems
deviated to suit certain purposes (like sibling comment about even
divisibility of 60) but usually came back to using 10. We've always needed to
count, been smart enough to count, and had 10 fingers readily accessible to
count, so I wouldn't count that theory out :)

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lou1306
I think the biggest strength of base 10 is not hand-counting (the OP and the
Babylonian/Chinese base-12 method are both superior in that regard), but ease
of performing pen-and-paper operations. You can literally teach a 6-year-old
to multiply huge numbers effortlessly.

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majewsky
If you use any other base for writing numbers down, it's just as easy to
perform pen-and-paper operations. The only problem with larger bases is that
the multiplication tables increase quadratically. Whereas a base-10
multiplication table has 100 entries, a base-16 table already has 256 entries.

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dTal
>a base-10 multiplication table has 100 entries

Not quite! You can safely ignore identities (0, 1, and 10 itself) so you only
have 8 numbers in your table. And multiplication is commutative so you only
need 8+7+6... (= (8+1)(8/2) as per Gauss) = 36 entries.

Base 16 would have (14+1)(14/2) = 105 entries. So proportional to base-10,
actually slightly harder than you said.

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curiousllama
The classic - detailed correction followed by "but yea you're totally right
anyway" lmao

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majewsky
A fine demonstration how "basically correct in two sentences" is better than
"technically correct in five sentences" in most situations.

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fredophile
I'm surprised no one has mentioned counting in binary on their hands yet. You
can get to 31 with just one hand.

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patricknixon
4

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moron4hire
13 (considering the thumb as the most significant digit, for obvious
evolutionary reasons)

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nvader
Thumb should be least significant, because the least significant digit changes
most often when counting, and therefore you want the most dextrous digit doing
that.

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captn3m0
My favorite is Chisenbop[0], the Korean finger-counting system, that lets you
count/add/subtract easily to 100. It isn't as intuitive, but it is quite fun.

[0]:
[https://en.wikipedia.org/wiki/Chisanbop](https://en.wikipedia.org/wiki/Chisanbop)

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tejtm
Some indigenous Americans had a wonderful octal counting system based on the
spaces _between_ fingers which becomes exponentially more awesome when you
hold small twigs, string, grass whatever between your fingers as placeholders
in your manual abacus.

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mavhc
If we could have seen one more planet in the sky maybe we would be counting in
8s, much easier for switching to binary then

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andrew_eu
I remember when I used to teach at a kids programming camp part of my
curriculum included teaching them to finger count in binary. It's fairly
straightforward to understand and some kids would write the base-10 equivalent
(1, 2, 4, 8, ...) on the back of their fingers to practice.

Occasionally a camper would ask why don't computers use base-3 instead of
binary. In fairness, with 10 trits you could count to almost 60k, way better
than silly binary's 1024. I imagine some of those campers went on to become
excellent surgeons.

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JoeAltmaier
Somebody published a paper (back in the 80's?) that posited, digital logic
should use base-3. They solved some equation and base-e was the optimum
(2.718...) and that is closer to 3 than 2.

But so much easier to do circuits 0-1 I guess. Or the science was wrong.
Anyway, just be glad we have the sensible binary system we have. Used to use
bi-quinary, ones-complement and other strange schemes. Took a surprisingly
long time to settle on twos-complement integers.

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drdeadringer
Some of the finger dexterity here I'm pretty sure I won't be able to do
without assistance or faking or similar; for example, my physically getting
the difference between "1" and "9" boarders on Vulcan-level fingering for me.
I am impressed.

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gumby
My mother grew up using a similar system using knuckles and positional
counting. I remember she taught it to me as a kid but I've forgotten. She's
Indian.

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hnzix
Counting knuckles and gaps across both hands from left to right also works for
tracking which months have 31 days (with February as the exception). Knuckle =
31 days, gap = 30 days.

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iamthemonster
It's actually quite interesting thinking about all the number systems you
could accommodate by counting on your fingers, and some of the interesting
difficulties (try holding your fingers out, then folding down only your index
and ring fingers... Not comfortable).

Using base 10 is probably one of the worst ways you could use your hands for
counting, funnily enough. Base 6 would be pretty convenient, quick and
comfortable (counting up to 35) - each finger on the right hand is the "units"
column and each finger on the left hand is the "sixes" column.

There's a compromise between complexity, comfort and capacity.

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yesenadam
Also re counting: we also have Bede to thank that we call this year 2020, and
not e.g. the 4th year of Trump :

"At the time Bede wrote the _Historia Ecclesiastica_ , there were two common
ways of referring to dates. One was to use indictions, which were 15-year
cycles, counting from 312 AD. There were three different varieties of
indiction, each starting on a different day of the year. The other approach
was to use regnal years—the reigning Roman emperor, for example, or the ruler
of whichever kingdom was under discussion. This meant that in discussing
conflicts between kingdoms, the date would have to be given in the regnal
years of all the kings involved. Bede used both these approaches on occasion
but adopted a third method as his main approach to dating: the Anno Domini
method invented by Dionysius Exiguus. Although Bede did not invent this
method, his adoption of it and his promulgation of it in _De Temporum Ratione_
, his work on chronology, is the main reason it is now so widely used."

[https://en.wikipedia.org/wiki/Bede#Use_of_Anno_Domini](https://en.wikipedia.org/wiki/Bede#Use_of_Anno_Domini)

I was just reading in his _History_ the other day, such a fascinating book.
It's a history of England (focusing on Christianity) from Julius Caesar to the
600s. His monastery was a renowned centre of learning, with _200_ books. Just
imagine trying to do historical research in England in 700AD..

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shakil
You can count to a 100 on a single hand easily. Imagine each finger has four
facets, and combining segments and joints you can count to 5 on each facet of
each finger, gives you the ability to count to 20 on a single finger, so 100
for the hand. I haven't tried it but combining both hands would then allow you
to go up to 10,000

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jguimont
Tuna auction is also using hand numbers like this
[https://youtu.be/H-eoIxfycf8?t=316](https://youtu.be/H-eoIxfycf8?t=316)

They also sometimes do the gestures with the hands under a sheet to do a
silent auction. Pretty impressive.

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todd8
The most interesting use of my fingers for numbers and computation were for
playing perfect strategy in the game of Nim (back in high school). I just
represented numbers between 0 and 15 in binary on one hand by slightly bending
the fingers corresponding to bit positions for binary digits.

Nim is a simple game played with coins or markers distributed into a number of
piles. Players alternately remove one or more markers from a pile of their
choosing. The player removing the last marker loses. The game starts with any
number of piles, typically 3 or 4, and any number of markers in each of the
piles.

Using one hand (and knowing binary) it’s easy to mystify opponents.

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forinti
I found something very interesting about roman numerals. If you had to set up
a physical score table for a game (say basketball), in base 10 you would need
10*3 digits (10 digits for each position in a 3 digit number).

If you try other bases, you'll find 3 is the cheapest (you'll only need 19
digits to show all numbers from 0 to 999).

But with roman numerals, you only need 16 (15 plus one for zero).

It is the most economical base by far. You would need I (3), V (1), X (4), L
(1), C (4), D (1), M (1), and N for nihil.

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dandare
I find it interesting that no culture used the binary system. It allows to
count to 1024 on 10 fingers.

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liotier
I just tried - comfortable practice requires more supple dexterity than I can
muster.

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dandare
Maybe you are doing something wrong - all agility the binary counting requires
is bending one finger per bit, which is the same as counting from 1 to 10.

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anandoza
There are 1024 configurations for counting in binary, and only 11 for counting
"normally". Some of those other ~1000 configurations are harder to do (like
having every other finger up). Mostly stuff with your ring finger.

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totetsu
Apart from my index finger and thumb, the tips of my fingers all kind of curl
together to some degree, so my roman one and two would look much the same, and
I have to strain to get a rough 5. I often wonder if I could retrain my brain
about this with enough time.

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gota
I'm also surprised how hard it was for me. All it took was counting up to 8 a
couple o times, trying to do it somewhat fast and visually-clear and I feel
the strain, particularly on my ring finger.

I could use it as a mnemonic device to help me "store" a number, perhaps, but
likely not to visually communicate numbers to others in an effective way

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rehevkor5
American Sign Language can represent numbers up to 999 with one hand, and
numbers past that with two hands (formally, though you could still be
understood if you were holding a beer in the other hand.) A useful skill to
have!

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Causality1
I find it interesting that, according to the chart, the Roman's were not only
comfortable flexing their pinkie finger without their ring finger, but so
comfortable they did it rather than flexing their index finger for 1.

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samatman
I habitually count from the little finger out to the thumb.

The 'one' sign, pinky out, is accomplished by locking the other three fingers
with the thumb.

Then I sort of flick the other three fingers out, and extend the thumb for
five. It's quite comfortable, and easier than going in the other direction.

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eru
It's interesting to see that they had a notation for zero in that system.

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louis8799
Interesting, if you ask a computer scientist what is the max number that can
be counted with two hands, he will say 2^10 = 1024. 9,999 is far from 10-bit.

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lifthrasiir
It is not binary because 1 through 3 and 7 through 9 bend the same finger but
at the different joints. As a result it is much more awkward to bend than
binary counting.

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DmitryOlshansky
It’s powerful. I recently contemplated that a hand has 6bit/sec or so
bandwidth.

5 fingers + two sides of the arm. Cool stuff isn’t it?

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jacobmoe
I can't move my pinky independently of my ring finger, so I can't do a unique
7 and 9.

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JoeAltmaier
That must be a thing. I have a sister and a son, same way.

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jacobmoe
Glad I'm not the only one. I was picturing myself being laughed out of the
Roman Forum.

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m463
I wonder if there's a scientific notation

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ineedasername
I just grow more fingers. Problem solved.

