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Finger counting

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mckeonj
318038.  Wed Apr 16, 2008 5:45 pm Reply with quote

There is another finger counting method taught in India by which the thumb and fingers of one hand can be used to register and operate on numbers up to fifteen; by counting phalanges.
A phalange is one section of a finger or thumb.
Pretend for the moment that the thumb is the first finger and has three sections, not two; also pretend that you don't need to calculate with numbers less than three.
Hold up one thumb for 3, and use the tip of that thumb as a pointer to count the phalanges on the index finger; 4, 5, 6; middle finger; 7, 8, 9; ring finger 10, 11, 12; ear finger; 13, 14, 15. Learn and remember the numbers for each phalange.
Now you have a built in calculator.
A couple of side notes:
A calculus is a pebble, as kept in the shepherds purse.
Herd animals are counted in sets of twenty; a score on the tally.
Shepherds use a set of counting words, such as 'yan tan lethery pethery pimp'; this was explored in an earlier thread with the interesting title bumfit post 185154

 
96aelw
318049.  Wed Apr 16, 2008 5:57 pm Reply with quote

Which links neatly to a New Guinean finger counting system in which the word for three and the left middle finger is bum rip. Rude words somehow never lose their appeal. post 257388 and following.

 
cupati
318144.  Wed Apr 16, 2008 8:43 pm Reply with quote

I tend to use finger counting, not for calculation, but for memory. By calculating the number in binary, then folding my fingers in the correct position, I am using two methods to reinforce the memory (and am storing the number in two places, my head and my hands). This is good when what you're having to do is dash off to a room of a given number, and really don't want to admit to the person who asked you to go that you believe your memory skills to be that poor.

Finger-counting can also be useful as a tally system, by moving your fingers to the next position whenever the event you've been expecting to recur does, with a certain inevitability.

 
Southpaw
318238.  Thu Apr 17, 2008 3:26 am Reply with quote

Good Gravy Cupati, that sounds complicated. Why not use a simple peg system?

 
cupati
318400.  Thu Apr 17, 2008 8:04 am Reply with quote

All it involves is a movement of the fingers, and you're set. Of course, as a maths student, I have a soft spot for number systems over words.

 
ColinM
318424.  Thu Apr 17, 2008 8:56 am Reply with quote

southpaw wrote:
Good Gravy Cupati, that sounds complicated. Why not use a simple peg system?

Wait, what? You seriously think memorising a list of a thousand different objects in order is easier than learning to count in binary? I have my doubts. Or have I misunderstood something about this peg method?

 
Southpaw
318449.  Thu Apr 17, 2008 9:39 am Reply with quote

Yes, though perhaps I wasn't precise enough in my naming it the peg system. What I actually mean is the Major Mnemonic System, a form of peg system. This involves assigning a (logically suitable) letter to the numbers 0-9, then using these letters to form a memorable word or set of words. Par example:

0 - z (and by extension s)
1 - l
2 - n (as n has 2 downstrokes)
3 - m (as m has 3 downstrokes)
4 - r (fourrrr)
5 - f/v
6 - b
7 - T
8 - gh and j
9 - g

For example, I happen to know that the hectarage of the parish of Chailey in West Sussex is 2491.32ha. I remember this with the phrase 'Energy Lemon', derived from NRGLMN.

Personally I find this kind of word play/visualisation easier to remember than binary, though of course it's horses for courses.

 
simonp
320224.  Sat Apr 19, 2008 2:05 pm Reply with quote

[quote="M"]
Quote:

How I wish I'd known how to do that as a child learning numbers.


Mrs P writes:
I use the 9 times table hands rule a lot with my class of 9 and 10 year olds as they seem to find the odd number tables the hardest to learn. I didn't know the 99 one, but I'll definately use it with some of my lower ability children who still have trouble with numbers over 10. Thanks! :-)

 
mckeonj
320312.  Sat Apr 19, 2008 3:57 pm Reply with quote

Using fingers for adding and subtracting is a good thing
Learning multiplication tables is good thing
Learning complements is handy, too.
Complements?
1 9
2 8
3 7
4 6
5 5
6 4
7 3
8 2
9 1
Boringly obvious, and remarkably useful in real life; when you see 7 it always has an invisible companion 3.
Less obvious complements are those of weekdays and months;
for example, one should simply know that Saturday is ten days after Wednesday, without using fingers; and July -3 is May.
Another useful skill is 'seeing' how many objects there are in a group, and word puzzle addicts often 'know' how many letters there are in 'syzygy'.

 
Andrew
320318.  Sat Apr 19, 2008 3:59 pm Reply with quote

mckeonj wrote:
and July -3 is May.

In what sense? :-s

 
simonp
320322.  Sat Apr 19, 2008 4:03 pm Reply with quote

The complements are aparrently now called "number bonds", by school type people.

 
npower1
320363.  Sat Apr 19, 2008 5:18 pm Reply with quote

Oh, goody, one of my hobby horses.


I never came across 'compliments' or 'number bonds' until I helped out in an adult numeracy class. Having been made aware of these ideas the whole concept of numeracy and its relevance to todays world became questionable. I see no need for anyone to be able to instantly give the result of 4 times 7 or being able to use paper and pen to discover a value for 27 times 36.

(An aside, there may well be an affect on educational attainments that learning such skills develops, but I'm not aware of any definitive research to support this.)

Oh, and don't get me started on the national curriculum for numeracy, which has room for improvement.

 
ColinM
320365.  Sat Apr 19, 2008 5:26 pm Reply with quote

Ah, Southpaw, that does make more sense. A mapping from digits to letters, then padding to make words, eh? Sounds odd to me, but I guess it's just a matter of practise. Seems like it'd get a bit awkward with repeated digits, though.

How about this for a compromise: convert the number to binary, then map 0s to vowels and 1s to consonants. You couldn't pad the word of course, but you'd have a fair few choices for most combinations. Repeated digits would still be a bit awkward though. Hmm.

As for these 'complements', I don't think I've ever heard them called that. Or anything, for that matter. Actually the first thing that sprang to mind was conjucates, though that's a rather different thing (and of less use to most people).

Can't do simple things with weekdays or months quickly though. It takes me ages just to remember what order the months come in. And how many days are in each. Heck, I can't even do alphabetical order quickly.

 
simonp
320448.  Sun Apr 20, 2008 3:40 am Reply with quote

npower1 wrote:

Oh, and don't get me started on the national curriculum for numeracy, which has room for improvement.


MrsP writes:

I understand there are problems with the National Numeracy Strategy as it didn't give you much scope for cross-curricular linking. The new Primary Framework seems to be approaching things differently.

 
npower1
320486.  Sun Apr 20, 2008 4:58 am Reply with quote

Simon and MrsP,

I did a Google search on 'Primary Framework Numeracy'. I found what looks like an official site. I was not impressed.

(1) it mixes numeracy and mathematics - I consider these as totally separate. Yes, you can learn some maths from becoming numerate but the objectives of each are different. Becoming numerate helps in dealing with the every day world; learning maths is learning logical thinking.

(2) it is aimed at year 6. By this age (10/11 years old) most children should have achieved fluency in numeracy.

 

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