Basic Calculator
Add, subtract, multiply, divide and percent, with exact answers and history.
Calculate
How to use this calculator
Tap the keys or type your calculation, and the answer appears as you go. Tap = to save it to your history, then keep calculating with the result. Tap a line in your history to bring that calculation back.
How it's calculated
The calculator follows the order of operations (BODMAS): brackets first, then powers, then multiplication and division, then addition and subtraction. Sums with + โ ร รท and whole-number powers are worked out exactly, so 0.1 + 0.2 shows 0.3. Percent works like a phone calculator: 50% is 0.5, and 200 + 10% is 220.
Worked example
12.5 ร (3 + 4) = 87.5. And 1 รท 3 gives 0.333333333333, with the exact fraction 1/3 shown underneath.
Frequently asked questions
Why does 0.1 + 0.2 show 0.3 here?
Many calculators work in binary decimals, which causes tiny errors like 0.30000000000000004. Phademy uses exact arithmetic, so the answer is clean.
How does the percent key work?
On its own, % divides by 100. After + or โ, it means a percent of the first number, so 200 + 10% = 220 and 200 โ 10% = 180.
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Last updated October 2026. Results are for learning and guidance; always check important work. Calculations run in your browser and are not stored.