A DOZENAL CALCULATOR FOR YOUR COMPUTER
by Gene Zirkel
One of our members, Michael Punter of England, has submitted a wonderful calculator for a computer.
Although it is written in C++, one does not need to know that programming language nor does one need to
have a copy of it installed on a computer.
Not only does this calculator work in both dozens and decimals, it easily switches back and forth between
the two. In fact if one adds “12 + 13" in decimals and then switches to dozenals before entering “=” the
result is duodecimal 21; and similarly if one adds “10 + 10" in dozenals and then switches to decimals
before entering “=” the result will be decimal 24.
Unlike some simpler calculators, Michael’s device includes logs and trig functions. The logs work in base
10, whether that symbol represents either a dozen or a ten. The trig works with four different angular
measures: degrees, radians, a full circle and a semicircle. This latter unit is from Tom Pendlebury’s
excellent work, TGM: a Coherent Dozenal Metrology Based on Time, Gravity & Mass wherein one zeniPi
(1 twelfth of p) is equivalent to 13; (15.) degrees.
The upper left corner reads Zen when calculator is in normal Dozenal mode and Dec when calculator is in
To the right of this the calculator displays an M if a non zero value is in memory & is blank otherwise.
Below left the calculator shows which of four possible modes of angle measure the trig functions are using.
See below, column 6 & end note 1.
Finally the current operation /, x, -, or + (if any) is displayed. Operations may be repeated using the last
value entered. Thus “4 x 2 x” displays 8 and entering a third “x” produces 14; (16.). This feature allows for
exponentiation with integral exponents. For example 23 can be found by entering “AC 2 x x x =”, and 2-3
can be found by entering “AC 1 / 2 / / / =”.
Non-integral exponentiation can be accomplished using logs. Thus 9½ = Anti log(½ log 9) which can be
found by keying “9 log /