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Basic Calculator

Simple four-function calculator with chain calculations, percentage, and keyboard support.

Calculator

Keyboard-ready
M
0
?
Keyboard shortcuts
Numbers: 09 .
Operators: + * /
Equals: Enter =
Clear: Esc
Backspace:
Percent: %

How It Works

This basic calculator operates like a standard handheld calculator. Enter numbers and operators to build calculations, then press = to evaluate. The result carries forward, so pressing an operator after = continues from the last result (chain calculations).


Chain calculations: Type 5 + 3 = to get 8, then × 2 = to get 16. The calculator remembers the previous result and uses it as the starting point for the next operation.


Percentage: The % button works contextually. On its own, 50% = 0.5. With an operator, 200 + 10% = 220 (10% of 200 is added to 200).


Edge cases: Division by zero displays "Error". Very large or small numbers are shown in scientific notation. The ± button toggles the sign of the current number.


Tips & Best Practices

Press = then an operator to continue calculating from the result.
Use % after an operator to calculate a percentage of the first number: 200 + 10% = 220.
CE clears only the current entry, while C clears everything.
All keyboard shortcuts work: 0-9, +, -, *, /, Enter (=), Escape (C), Backspace.

Frequently Asked Questions

How do chain calculations work?

When you press = to get a result, the calculator remembers it. If you then press an operator (like ×), it uses the result as the first number in the next calculation. For example: 5 + 3 = 8, then × 2 = 16.

The % button has two behaviors. Without a preceding operator, it divides by 100 (so 50% = 0.5). With a preceding operator, it calculates the percentage of the first number. For example, typing 200 + 10 % = gives 220, because 10% of 200 is 20, and 200 + 20 = 220.

Dividing by zero displays 'Error'. Press C to clear and start a new calculation.