Basic Calculator

Keyboard Controls (Numpad equivalents should work too; Copying values with CTRL+C is supported):

Clear: C or ⇐ BackSpc
Clear Entry: SHFT + C or SHFT + ⇐ BackSpc
Numbers: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
Operators: +, -, *, / - using shift where necessary; x also works for multiplication
Equals: = or ↵ENTER
Change sign: SHFT + -

JUNE 2021 UPDATE: Greatly improved readability of the visual code, making it more concise where possible. Improved and modernized keyboard logic.

Almost all you see here is HTML/CSS/Javascript; no SVG's were used. I used Python to create code for the star-field in my space theme. I hope you bookmark this calculator, come back often, and that it is of use to you.

This has been a great exercise in trying to account for every kind of problem that can arise. So if it's broken, it means it can be improved! I have found an appreciation for the creation of the most basic calculators. Some items I had to account for include:

Preventing 'division by zero' attempts
Preventing successive zero entries at the start of a number
Display-limit of characters so numbers couldn't extend beyond the virtual display

This included defining situations where I wanted scientific-notation or wanted to limit the output

Ignoring successive operator entries and allowing you to change the active operator (if you pressed the wrong one)

* Disclaimer of Use: Please feel free to use in any way you want as long as you leave the title of the calculator (in the bottom left corner) in tact. In your code, you can simply put a link to this page.