Finger counting

Finger counting, or dactylonomy, is the art of counting along one's fingers. Though marginalized in modern societies by Arabic numerals, formerly different systems flourished in many cultures, including educated methods far more sophisticated than the one-by-one finger count taught today in preschool education.

Finger counting can also serve as a form of manual communication, particularly in marketplace trading – including hand signaling during open outcry in floor trading – and also in games such as morra.

Finger counting varies between cultures and over time, and is studied by ethnomathematics. Cultural differences in counting are sometimes used as a shibboleth, particularly to distinguish nationalities in war time. These form a plot point in the film Inglourious Basterds, by Quentin Tarantino, and in the novel Pi in the Sky, by John D. Barrow.

Cultural differences

In various regions, different methods of finger counting are used. In Western and Central Europe fingers are extended, beginning with the thumb and finishing at the pinky. In Eastern Europe, fingers are folded towards the palm in reverse order. In the United States, counting usually starts on the pointer finger and ends on the thumb.

Chinese number gestures count up to 10, and themselves exhibit some regional differences.

Japan

Japanese uses separate systems for counting for oneself and for displaying numbers to others, which both proceed up to ten. For counting, one begins with the palm open, then counts up to five by curling up (folding down) the fingers, starting from the thumb – thus one has just the thumb down (and others extended), while four has only the pinkie extended, and five has a fist. One then counts up to ten by proceeding in the reverse order, extending the fingers, starting at the pinkie – thus six is the same as four, seven the same as three, and so forth, with ten ending with the palm open. While this introduces ambiguity, it is not used to present to others, so this is generally not a problem. When displaying for others, one starts with the hand closed, and extends fingers, starting with the index, going to the pinkie, then ending with the thumb, as in the United States. For numbers above five, one uses an open hand (indicating five) and places the appropriate number of fingers from the other hand against the palm (palms facing each other) – so six has the index finger against the palm, and so forth. To display ten, one presents both hands open and palm outwards.

Historical counting

Complex systems of dactylonomy were used in the ancient world. This counting was in use in Persia in the first century CE, and thus may have originated there; it continued in the Islamic world through the middle ages, and is mentioned in poetry and the Quran. A very similar form is presented by the English monk and historian Bede in the first chapter of his De temporum ratione, (725), entitled "De computa vel loquela digitorum", which allowed counting up to 9,999 on two hands, though it was apparently little-used for numbers of 100 or more. This system remained in use through the European middle ages, being presented in slightly modified form by Luca Pacioli in his seminal Summa de Arithmetica'' (1494).

See also

Finger binary

Chisanbop

Tally marks

Prehistoric numerals

Colombian numerals

Chinese number gestures

Notes

References

. Translated from the French by David Bellos, E.F. Harding, Sophie Wood and Ian Monk. Ifrah supports his thesis by quoting idiomatic phrases from languages across the entire world.

; 2nd edition, Brown University Press, 1957; reprint, New York: Dover publications, 1969; reprint, New York: Barnes and Noble Books, 1993.

External links

American Sign Language">counting in American Sign Language

Further reading

The Universal History of Numbers, Georges Ifrah