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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

◀️ Issue: Whole Number 88z (104d) | Vol. 44z (52d) No. 1 | Year 11ABz (2003d) ▶️



Click to view PDF

Editor: Prof. Jay Schiffman

Contents:

  • President’s Message | Jay Schiffman
  • Drastic Measures: The Metric Assault on American Standards | Peter Seymour
  • Mailbag
    • Cyrillic Characters | Jene Farmer
    • Duodecimal Application in Chemical Nomenclature | John McLeod
    • Linux | Brian Dean | bc calculator in Linux can output in any base
    • Dozenal Watch? | Dr. Paul Rapoport
    • Let’s Use L for Ten | Bob Sindeldecker
    • Metric Only Objection | William J. Holdorf
    • Can You Help? | Greg Martin
    • National Duodecimal Week? | Jean Kelly
      • National Duodecimal Duodecade: dozen days from twelve noon December twelfth to twelve noon December twenty-fourth, annually
      • National Duodecimal Week: the full week from Sunday to Saturday contained therein
  • Problem Corner
  • Minutes of the Annual Board and Membership Meetings — 11AAz (2002d) | Christina Aiello & Alice Berridge
    • Board of Directors Meeting
    • Annual Membership Meeting
      • Treasurer’s Report | Allice Berridge
      • Editor’s Report | Jay Schiffman
      • Annual Meeting Committee | Alice Berridge & Gene Zirkel
      • Nominating Committee | Alice Beridge
      • Awards Committee | Gene Zirkel
      • Other Business
        • John Impagliazzo | digitizing The Bulletin
        • Hal Melnick & Michael Cook | prospects of teaching bases at Bank Street School/College
        • Jay Schiffman | A Most Appealing Integer, Twelve — Six Dozen Somewhat Intriguing Ideas Where Dozens Play a Role
  • Why Change?
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.