- Pentimal system
The

**pentimal system**( _sv. pentadiska siffror) is a notation for presenting numbers, usually by inscribing in wood or stone. The notation has been used inScandinavia , usually in conjunction torune s.The notation is similar to the older

Roman numerals for numbers up to 9 "(I - VIIII)". Unlike the Roman notation, thenotch es are placed vertically on the stem or "stav" 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 the

golden numbers , 1 - 19 onRunic calendar s ( _sv. runstavar, _no. kalenderstavar, also known as "clogs"). [*[*] The numbers are commonly found in*http://www.monas.nl/think/runecalendars.htm think - rune calendars*]Modern Age and possibly Early Modern Age calendar sticks. It is unknown if they were in use in theMiddle Ages , let alone in theViking Age . On older runic calendars, 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. The "Computus Runicus ", originally from1343 , but collected and published byOle Worm in the 17th century, used this alphabet notation. [*" [*]*http://www.arild-hauge.com/computus_runicus.htm Computus Runicus - The Runic Calender From Gotland From 1328.*] " Described byOle Worm Most

runic text s, including the Viking agerunestone s, use nonumeral system ; instead, numbers are simply spelled out.**Positional notation**In some peculiar instances runic numbers have been used as

numeral s in abase ten positional system, replacing theArabic numerals . It is unknown if this use existed before the 19th century.The oldest authenticated use of this notation is in 2004.

This positional notation however appears on two unrelated sets of rune stones allegedly discovered in

North America . The first is theKensington Runestone found in 1898, the second are the threeSpirit Pond runestones found in 1971. All refer to pre-ColumbianNorse exploration of the Americas .The authors of the North American rune stones do not seem to understand the positional notation or the concept of zero. The rune for 10 is used interchangeably for 0, 10, and <1,0> with little consistency. The "inscription stone" from Spirit Pond contains the sequences "ahr:011" and "ahr:00", [

*[*] which have been read as "year*http://www.sjolander.com/viking/rune/spirit.htm Transcription of Spirit Pond Number 3*] , lines 3 and 81011 " and "year1010 " respectively. It is unclear if the notation can represent all numbers unambiguously; for example, it may not be possible to distinguish 1010 from 100.The use of this otherwise unknown numeral system has been seen as evidence that the North American rune stones are

hoax es.**References****ee also***

Ogham

*Biquinary

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