Pentadic numerals

The notation is similar to the older Roman numerals for numbers 1 to 9 (I, II, III, IV, V, VI, VII, VIII, IX).

[1] Unlike the Roman notation, there are only symbols for numbers one ("I") and five ("U"), protruding off the side of a vertical stroke, or stem, which has no numeric value by itself.

[a] The widest use of the notation is in presenting the Golden Numbers, 1–19 on Runic calendars (Danish: kalenderstave, Swedish: runstavar, Norwegian: kalenderstavar, also known as clogs).

For example, the Computus Runicus manuscript, originally from 1328, but collected and published by the Dane Ole Worm (1588–1654), uses this futhark notation, and not the pentadic numerals under discussion here.

The oldest authenticated use of this notation is in the notes of an 18 year-old journeyman tailor, Edward Larsson, that are dated to 1885 in pentadic runes.

Edward Larsson's notes from 1885 show the use of "pentadic" runic numerals to replace the Arabic numerals in representing dates. The number shown here as zero is normally used for ten.