Dozenal Calculator

About

A full featured RPN calculator, 

• Easy Doz It when working in dozenal (base twelve), or

• RPN Crunch when working in decimal (base ten)

User Interface, normal keys & shifted keys

Features

• Reverse Polish Notation (RPN) Stack

• On-screen keypad, or keyboard entry

• Numbers in 64 bit double precision

• Numbers in radix bases: 2 (binary), 10 (decimal), 12 (dozenal, duodecimal), or 16 (hexidecimal)

• Number layout can be optimized for dozenal or decimal.

• Fractional separator (i.e. decimal point), thousand separator, and ten, elv symbols can be set to match locale or dozenal conventions.

• Math, Trig, Logs, Finance, Probability, Statistics, Vectors, and Date operations

• Conversions and Constants

• Real time currency rates

• Stack and settings saved between uses (not demo version)

• History of past operations

• Paste/Copy access to clipboard

• Runs on any device with Chromium compatible browser

• In app help with drop down navigation

Basic Operation

Startup: The calculator starts up with same stack contents and mode state from last shut down (not demo version).

Stack: The stack has 4 registers. 

• T register (top)

• Z register

• Y register

• X register (display)

You push all numbers (on which you'll perform operations) onto the stack with 'enter' key (push). After a math or stack operation, the next number is automatically pushed onto stack (without 'enter' key).

Before performing a math operation, the stack is saved as last stack, and the operands (number(s), under which the operation operates), are popped from stack. The result is pushed onto stack. When more operands are popped than results pushed, 4 registers are maintained by pushing a copy of T to top of stack.

Numbers: You use the blue keys or typed digits to enter numbers. Letter digits are upper case. 

Math operations: For math operations, you use the orange, dark orange, bright green, bright cyan, and light purple keys, or typed lower case letters.

Shift key: The shift key will show another level of stack, number, and math operations.

Dozenal Configuration Option

Dozenal Information

Users are encouraged to experiment with Dozenal (base twelve, duodecimal). 

There's a community of people who advocate using dozenal instead of decimal (base ten). A dozen is divisible by 2, 3, 4, 6, while ten is only divisible by 2, 5. There's a dozen months, a dozen hours in a half day. Each of our 4 fingers have 3 sections. This allows arithmetic in dozenal on our fingers. Measurement systems would be changed to powers of dozens rather than tens.

There's dozenal information at American dozenal society, and the British dozenal society. You can read my paper, The Mighty Dozen.

Revision History

Oct 2022, ver 1.3, Added key queue, cleaned up stack implementation, added portrait and landscape view, and added help page. 

Feb 2023, ver 1.4, Added base mode (doz or dec (base ten)), added format mode (fix or eng), places, angle mode (rad or deg), and ten, eleven digit options (A, B; or ↊, ↋;). In doz base mode, fractional separator is semicolon. In dec mode, fractional separator is dot. User stack and mode settings stored between uses (encrypted). Added shift key, and additional math commands for int, trigonometry, logarithms, and finance commands. Added app title and icon in browser tab. Added simpleDoz logo and fobsplace Apps logo images to help. Updated help with new features, and improved readability.

Mar 2023, ver 1.5, 1.6, 1.7, Added command button row, so now only 1 level of shift. Improved landscape and portrait display to use full screen real estate. Added probability functions. For ten, eleven digits, rotated 2, 3 are not supported on all devices, e.g. Android mobile devices. T, E added as an additional ten, eleven digit option (A, B; ↊, ↋; or T, E). Mode settings changed from toggle keys to drop down selectors.. On desktop, selectors and keys have hover highlight. Changed probability keys names, from 'fact', 'perm', 'comb' to 'n!', 'npr', 'ncr'. Fixed 'lasts' so restores stack and 'lastx' restores X register using current mode settings for display.  Added category selector for navigation through help text. Added keypad layout for 'dec' 0 + 3x3 grid. Keypad layout for 'doz' remains 3x4 grid.  Shift key toggles colors to signal shift state. Probability and finance keys switched positions to be more consistent with RPN Crunch layout. Optimized text and key sizes for phone use. Updated help for new changes. Added shifted keys screenshot to help.

Apr 2023, ver 1.8, Improved help.

May 2023, ver 1.9, fixed rounding error, e.g. 0;186A, places = 2, is now, 0;19, (not 0;18). Improved web app update help. Shift key when shifted is now colored cyan (rather than reddish orange, in order to respect the red reserved for danger convention). 

Jun 2023, ver 1.10, in help, explanation of key queue, and probability examples improved.

Aug 2023, ver 1.11, added XE, XL options for ten, elv symbols. TE become default ten, elv digits choice. Fixed digi (digits increment) change so selector display updates. Added digd (digits decrement) word command. Changed ten, elv symbol code to use baseConv lib, ver 12. Updated help to explain XE, XL, and digd. Help About version text uses base and digits settings. As state data structure has changed, a one time 'reset' is done at startup. This results in loss of prior state data (stack and settings return to default values).

Sep 2023, ver 1.12, added  ten, elv digit options:  δε (delta epsilon), τε (tau epsilon). Uses baseConv lib 14. All images hosted at imgbb.com, (rather than google drive) to improve reliability of image loading, and provide Firefox compatibility.

Aug 2024, ver 1.13, 1.14, embedded images into code. No more hosting service time out issues, imgbb.com. Improved server data storage/retrieval between uses. Updated browser icon retrieval.

Dec 2025, Jan 2026, ver 4.00, 4.01, Simple Doz renamed to Easy Doz It. Merged Easy Doz It and RPN Crunch. When calculator is in dozenal mode (base twelve), app is named Easy Doz It. When in decimal mode (base ten), app is named RPN Crunch. RPN Crunch keypad adopts Easy Doz It's simpler layout, less keys, with the same operations as RPN Crunch. For Easy Doz It, many new features adopted from RPN Crunch. Many other minor improvements. Help file updated and improved. Examples are specific to base setting. Removed dozenal calendars and time options. Removed ten elv options, δε (delta epsilon), X E.