Calculator

Calculator for iPhone
Download on theApp StoreComing soon

Calculator is a calculator app for iPhone made like a 1970s desk machine. Twenty machined keys, a yellow column for the operations and nine red figures behind glass.

Calculator works like the machine on a desk in 1978, with exact arithmetic underneath. It calculates left to right as you type, repeats the last operation when you press = again, and never loses a digit.

DECIMAL decides how many places you see; SOUND turns the key clicks off. Widgets keep the last number on the Home Screen and the Lock Screen.

Add up a bill, work out a percentage, check a total: it calculates left to right as you type and never loses a digit.

Calculator, calculator for iphone, seen from the front at an angle
Calculator from the back
Nine red figures

Nine red figures

A seven-segment display in a window, slanted like the desk machines of the seventies. Unlit segments stay faintly visible, as they do on the real thing.
Keys with travel

Keys with travel

Every key goes down and comes back up, with a click recorded from real buttons. No two presses in a row sound the same.
Decimals on a knob

Decimals on a knob

Turn DECIMAL to round the display to 0 to 4 places, or to F to fill the window. The number underneath stays exact.

Specifications

Display
Nine seven-segment figures
Arithmetic
Exact decimal, left to right, repeated equals, percent
Sound
Recorded keys, switchable
Privacy
No account, no tracking, nothing leaves the phone
Requires
iPhone with iOS 18 or later

Questions

Is the arithmetic exact?

Yes. It uses exact decimal arithmetic underneath, so 0.1 + 0.2 is 0.3. The DECIMAL knob only rounds what you see.

Does it do percentages?

Yes. The % key works the way it does on a desk machine: 200 + 10 % gives 220.

Is there a widget?

Yes. Small and wide Home Screen widgets and Lock Screen widgets show the last number on the display; a control in Control Center opens the calculator.

Can I turn the key sounds off?

Yes. The clicks are recorded from real keys and can be switched off.

Which iPhone do I need?

Any iPhone running iOS 18 or later.

Does Calculator exist as a physical device?

Not yet. Calculator is a concept made as a digital object: designed and engineered like a real calculator, but it exists only on your iPhone. If you make hardware and would like to produce it in commercial quantities, we are open to collaboration: hello@objectism.app.

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