As to our English five we might see a beautiful reasonableness in naming it from the fingers of our own mathematical hands. We stick up our fingers in reckoning; the first task of our nursemaid mathematicians at school is to teach the child that sums are no longer to be done on the fingers but on slates with pencils. Thereafter follows mental arithmetic with a new series of tortures all its own.

But in the islands of our study fingers go not up but down for the count. The hand with its digits displayed coram publico is zero, cipher, naught. It is the clenched fist which counts most, it reckons five; a usage paralleled, to be sure, in our idiom of that noble art of defending ususally most ignoble selves, 'I put my bunch of fives in his -' mug, was it? Or peeper? Or possibly breadbasket, this being before the days when solar plexus had given to the ring the dignity of astrological anatomy. The five of the clenced fist I recall from many an island race.

Let me, however, confirm my testimony from an authority who believes that five is the hand, Dr. Codrington (Melanesian Languages 222, note 1):

The way of reckoning on the fingers differs in various islands. In Nengone the fingers are turned up and brought together at five. In the Banks Islands the fingers are turned down. This is often done with the spoken numerals, often without the use of words. The practice of turning down the fingers, contrary to our practice, deserves notice, as perhaps explaining why sometimes savages are reported to be unable to count above four.

The European holds up one finger, which he counts, the native counts those that are down and says 'four'. Two fingers held up, the native counting those that are down, calls 'three'; and so on until the white man, holding up five fingers, gives the native none turned down to count. The native is nunplussed, and the enquirer reports that savages can not count above four."

(William Churchill, The Polynesian Wanderings.)