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Dozenal Society of America
Promoting base twelve and alternative base mathematics
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The Dozenal Society of America
The DSA is a voluntary, nonprofit education corporation, organized for the conduct of research and education of the public in the use of dozenal (also called duodecimal or base-twelve) in calculations, mathematics, weights and measures, and other branches of pure and applied science.

The Duodecimal Bulletin: Chronology

Below are links showing the various stages of the development of the Bulletin, in groups of a dozen issues. Each is preceded by a brief summation of the unquade by our most recent editors, Michael deVlieger and John Volan, who offer fascinating insights into the history of our Society. The human dimension contained in these pages is worth appreciating as much the mathematical treasures!


Last Issue to First | First Issue to Last | Chronology
Link to First Bulletin Unquade

00–0Bz (00–11d)

1161–1164z (1945–1948d)
Link to Second Bulletin Unquade

10–1Bz (12–23d)

1165–116Bz (1949–1955d)
Link to Third Bulletin Unquade

20–2Bz (24–35d)

1170–1175z (1956–1961d)
Link to Fourth Bulletin Unquade

30–3Bz (36–47d)

1176–1184z (1962–1972d)
Link to Fifth Bulletin Unquade

40–4Ez (48–59d)

1185–1194z (1973–1984d)
Link to Sixth Bulletin Unquade

50–5Bz (60–71d)

1195–1198z (1985–1988d)
Link to Seventh Bulletin Unquade

60–6Bz (72–83d)

1198–11A0z (1988–1992d)
Link to Eighth Bulletin Unquade

70–7Bz (84–95d)

11A1–11A6z (1993–1998d)
Link to Ninth Bulletin Unquade

80–8Bz (96–107d)

11A7–11B0z (1999–2004d)
Link to Tenth Bulletin Unquade

90–9Bz (108–119d)

11B1–11B6z (2005–2010d)
Link to Eleventh Bulletin Unquade

A0–ABz (120–131d)

11B7z–now (2011d–now)
Copyright © 11B9–120Az (2013–2026d). The Dozenal Society of America. Contact Us.
Creative Commons License
This site and the documents on it are licensed under a Creative Commons Attribution 4.0 International License.

This site expresses numbers in alternative bases, particularly dozenal (also called duodecimal, or base twelve).
The DSA does not endorse any particular notation or pronunciation scheme for alternative bases.
However this site defaults to the following to ensure online readability across all platforms:
“Computerese” uppercase letters represent transdecimal digits: A = ten, B = eleven, C = twelve, etc.
Single-character subscripts annotate bases: d = decimal, z = dozenal, x = hexadecimal, etc., e.g., 2014d = 11BAz = 7DEx.

(0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 ...)d
(0 1 2 3 4 5 6 7 8 9  A  B 10 11 12 13 14 15 16 17 18 19 1A 1B 20 21 22 23 24 25 26 27 28 29 2A 2B 30 ...)z
(0 1 2 3 4 5 6 7 8 9  A  B  C  D  E  F 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20 21 22 23 24 ...)x

PDF documents on this site reflect changing practices among dozenalists over the years:
Various symbols have been used to represent digits ten and eleven:
Dwiggins 𝒳 and Ɛ (often rendered X and E); Bell Telephone * and #; Pitman turned 2 and 3 (↊ and ↋); etc.
Italics were once used to distinguish dozenal numbers from decimal: e.g. 0.5 = 0.6.
Later, semicolon became a separate‑identity “dozenal point”, versus period as “decimal point”: e.g., 0.5 = 0;6.
However, subscript base annotations provide a more versatile solution that is least‑change: e.g., 0.5d = 0.6z = 0.8x

Dozenal offers superior divisibility over decimal, which can make everyday arithmetic easier to learn:
⅙ = 0.2z | ¼ = 0.3z | ⅓ = 0.4z | ½ = 0.6z | ⅔ = 0.8z | ¾ = 0.9z | ⅚ = 0.Az
⅙ = 0.1666…d | ¼ = 0.25d | ⅓ = 0.333…d | ½ = 0.5d | ⅔ = 0.666…d | ¾ = 0.75d | ⅚ = 0.8333…d

EACH ONE, TEACH ONE.