How to use it
- Tap the digits, or type them — the number keys, operators, Enter for equals and Backspace all work.
- The faint line above the result keeps the expression you are building, so a long chain stays readable.
- Copy the result copies the number currently on screen.
How percent behaves
The percent key follows the convention of a desk calculator, not of a programming language. After an operator it reads the number as a share of the first operand, so 200 + 10 % gives 220 rather than 200.1. On its own it divides by a hundred. This is what people expect when adding VAT or taking a discount, and it is the single place where cheap calculators differ most from each other.
Numbers are grouped with commas and use a decimal point, following the locale of this page. Division by zero shows an error rather than infinity, and the display holds fifteen significant digits before switching to exponent form.
Keyboard
- Digits and
.enter numbers;+ - * /set the operator. - Enter or
=evaluates, Backspace erases a digit, Escape clears. %applies percent to the pending operation.
Questions
Does it work on a phone?
Yes. The keypad shrinks to fit a narrow screen and stays tappable; nothing needs installing.
What does the percent key do exactly?
With a pending operation it treats the entry as a percentage of the first number: 200 + 10 % gives 220. Pressed on its own it just divides by 100.
Is what I type stored?
No. The arithmetic happens in your tab and nothing is sent to affpapa.org. Reload the page and the calculator starts from zero.
Why does a long result switch to e-notation?
Past fifteen significant digits a decimal display stops being readable, so the result is shown as an exponent instead of being silently rounded.
