Pentimal system is a notation for presenting numbers, usually byinscribing in wood or stone. The notation has been used inScandinavia, usually in conjunction torunes.
The notation is similar to the olderRoman numerals for numbers up to 9(I - IIIIV). Unlike the Roman notation, theticks are placed vertically on a stem orstav of the rune. The number 4 is represented by four horizontal lines on the stem, 5 is represented by what looks like an inverted letterU. 10 is represented by two U's opposing each other. Numbers up to 19, or even 20, can be represented by a combination of I's and U's.
The widest use of the notation is in presenting thegolden numbers, 1 - 19 onRunic calendars, also known asclogs). The numbers are commonly found inModern Age and possiblyEarly Modern Age. It is unknown if they were in use in theMiddle Ages, let alone in theViking Age. On older runic calendar, a different notation for representing the golden numbers was used; the 16 letters ofYounger Futhark represented the numbers from 1 to 16 with three special runes used for the numbers 17 to 19. TheComputus Runicus, originally from1343 put collected and published byOle Worm in the 17th century used this notation.
Mostrunic texts, including the Viking agerunestones use nonumber system, instead numbers are simply spelled out.
In some peculiar instances runic numbers have been used as numerals in an base-ten positional system, similar to the Arabic numbers. It is unknown if this use existed before the 19th century.
The oldest authenticated use is in the notes of an 18-year-old journeyman tailor, Edward Larsson, the contain the date 1885 in runes. A copy of the note was published by theInstitute for Dialectology, Onomastics and Folklore Research in Umeå in 2004.
This positional notation however appears on two unrelated sets of rune stones allegedly discovered inNorth America. The first is theKensington Runestone found in 1898, the second are the threeSpirit Pond runestones found in 1971. Both refer to pre-ColumbianNorse exploration of the Americas but are modern day hoaxes.[1][2][3]
[...] every Scandinavian runologist and expert in Scandinavian historical linguistics has declared the Kensington stone a hoax [...]
