“In body part tally systems, the names of certain body parts also function as numerals. Counting starts on the little finger of the left hand (number 1) which the speaker touches or holds in some way with the fingers of the right hand. Moving past ring finger (2), middle finger (3), and index finger (4) the speaker reaches the thumb (5), after which he or she climbs the left arm, usually starting with the wrist (6), then the lower arm (7), the elbow (8), the upper arm (9), and the shoulder (10). After the points on the hand and the points on the arm, points on the head (for example neck, ear, eye, nose and crown of the head) are used.
“The top of the head is generally the turning point of the system, and then counting continues down the opposite side of the body until the little finger of the right hand is reached. Many languages use a prefix meaning ‘other side’ for the body parts as they are named after the turning point. Although people know the distinction between right and left, and have terms in their languages for ‘right’ and ‘left’, these terms are not used in the counting system. In fact, the systems work just as well if the speaker starts on the right side; but since most people are right-handed, they normally begin counting on their left.
“After the full number of body parts has been reached (once right round from the little finger of the left hand to the little finger of the right hand), some languages seem to extend the system by adding a word like ‘again’ or ‘bring forth.’
“To illustrate this general outline of body part tally systems, I will describe the Korowai system in some detail. Korowai is spoken in the area between the upper Becking and [Pulau] rivers of south-east [West Papua], Indonesia. The Korowai body part number system starts as follows:
1 — senan — little finger
2 — senanafül — ring finger
3 — pinggu(lu)p — middle finger
4 — wayafül — index finger
5 — wayo — thumb
6 — gédun — wrist
7 — lafol — lower arm
8 — bonggup — elbow
9 — labul — upper arm
10 — main — shoulder
11 — khomofekholol — neck
12 — khotokhal — ear
13 — khabéan — head
“When khabéan ‘head’/’thirteen’ — is reached, counting on the right hand side of the body begins, with the word mén ‘other side’:
14 — mén-khotokhal — ear on the other side
15 — mén-khomofekholol — neck on the other side
16 — mén-main — the other shoulder
17 — mén-tabul — the other upper arm
18 — mén-mbonggup — — the other elbow
19 — mén-tafol — the other lower arm
20 — mén-nggédun — the other wrist
21 — mén-wayo — — the other thumb
22 — mén-wayafül — the other index finger
23 — mén-pinggu(lu)p — the other middle finger
24 — mén-senanafül — the other ring finger
25 — mén-sénan — the other little finger
“Some Korowai informants have told me that when 25 is reached, the highest number after one round, a speaker can continue counting by adding the prefix laifu ‘produce’ to the body part names and start again with the little finger of the left hand going up again to the turning point:
26 — laifu-sénan — produce-little finger
27 — laifu-senanafül — produce-ring finger
. . .
38 — laifu-khabéan — produce-head
“This would extend the body part system of Korowai to 38. However, I have never heard such extended numerals used outside discussion with informants.”
Source: Lourens de Vries in The Bible Translator 1998, p. 409ff.
See numbers in Ngalum, large numbers in Angguruk Yali, numbers in Kombai, and hundred sheep.