Dozenal Calc vs Parolejo

A "dozenal calculator" — a scientific calculator that computes not in tens, but in twelves. With its own symbols for the digits. What base 12 can do that base 10 can't In the decimal system, 1/3 is an infinite repeating fraction (0.333…). In base 12 it's short and exact: 0.4. Sixths, ninths, and every fraction whose denominator is built from twos and threes also become finite in dozenal. No coincidence: twelve has six divisors, ten only four. Dozenal Calc computes exactly — a rational track runs in parallel with floating-point arithmetic. Repeating fractions appear with a bar over the recurring digits, for example 1/7 as 0.186A3 with a repetend bar. Features • Basic arithmetic, parentheses, signs • Power, square root, nth root, logarithm to any base • Trigonometric and hyperbolic functions including their inverses • Constants π, e, φ, √2; factorial, absolute value, reciprocal, modulo • Parallel addition (a⊕b) for resistor circuits • Memory (STO/RCL/MC) with exact rational preservation • Angle modes DEG / RAD / GRAD • Numeral-system switch (base 12/10) in the settings — input AND result, applies to both calculators • Light and dark theme Unit converter One swipe to the left opens the second calculator: it converts imperial and metric units into one another — length, area, volume, weight, time, angle, money (£/sh/d), temperature and more. Compound entries like 3 ft 5 in, breakdown into part units, and math right inside the entry (× ÷ ⊕ ^ √ log) with memory and constants. Results travel between the two calculators at the press of a key. A color code keeps the worlds apart: green for the world of ten (metric, base 10), violet for the world of twelve (imperial, base 12). Hands-on theory — now with pictures A richly illustrated read explains why twelve in particular is a special number, in three blocks: • Twelve and the World — from the dodecagon and dodecahedron through pyrite, garnet, viruses and quasicrystals to music, art, architecture and calendars • Dozenal Mathematics — divisors and periods, the number bases compared, a history of place-value systems • Dozenal Society — the movement for twelve, new digits for ten and eleven, the TGM measurement system and related dozenal calculators Many chapters show public-domain historical illustrations — from Haüy's pyrite plate through Leonardo's dodecahedron to Vermeer's balance — each with a tappable source citation. Plus a dedicated unit theory on measure and number, two illustrated operating manuals for both calculators, and recommendations for dozenal-friendly calculators on every platform. Fourteen languages Deutsch, English, Français, Español, Italiano, فارسی, Русский, Gaeilge, हिन्दी, 简体中文, 繁體中文, Cymraeg, 日本語, العربية — freely selectable in the info menu. What Dozenal Calc doesn't do • No ads, no tracking, no analytics • No internet connection, no permissions • No personal data The app works completely offline. What you type stays on your device. Who is it for? For teachers who want to show how a different number system transforms everyday work with fractions — and for anyone who wants to see mathematics from an unfamiliar perspective. License: MIT. Contact: dozenal@weltanschauung.app

Learn Esperanto offline, at your own pace, with a complete beginner course in your pocket. Parolejo combines a structured 12-lesson Zagreb-method course, narrated audio, flashcards, a large dictionary, and grammar reference into one app that works entirely without an internet connection. No accounts, no ads, and no payments. Whether you are starting from zero or brushing up, Parolejo gives you everything you need to read, hear, and practise Esperanto. What you get: - 12-lesson Zagreb-method course: clear, proven lessons that take you from your first words to real sentences, with text and interactive exercises. - Narrator audio at your pace: hear each lesson read aloud, slow it down (0.25x to 1x) to catch pronunciation, loop or jump back 10 seconds to repeat a phrase, and resumes where you left off. Lock-screen and background controls keep it playing with the screen off. - Tap-to-translate reading (beta): read "La novaj vestoj de la imperiestro" and tap any word for an instant translation. - Flashcards and Practice: review and drill the course vocabulary to make it stick. - 63,771-entry ESPDIC dictionary: look up Esperanto to English, with labels in your chosen course language. - Grammar reference and appendices: explanations and tables whenever you need them. - Adjustable text size: scale the lesson and reading text to read comfortably. - 30+ interface languages: use the app in the language you are most comfortable with. Attribution: The original 12 lessons content is provided under Creative Commons licenses (CC BY and CC BY-ND). The ESPDIC dictionary is provided under CC BY 3.0. Parolejo is based on the course at esperanto12.net. Additional content in future releases may be subject to different licensing. Questions or feedback? Email support@parolejo.app