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Decimal Calculator
Add, subtract, multiply and divide decimal numbers with exact arithmetic. Try 0.1 + 0.2 — ordinary calculators answer 0.30000000000000004; this one answers 0.3, because it does decimal maths the way you learned it, not with binary floating point.
Why normal calculators get 0.1 + 0.2 wrong
Computers store decimals in binary, and 0.1 has no exact binary form — so 0.1 + 0.2 comes out as 0.30000000000000004. This tool does the arithmetic on the decimal digits directly (exact integer maths under the hood), so money and measurements come out clean.
Division
Division is exact up to 12 decimal places, then rounded — 1 ÷ 3 gives 0.333333333333. Repeating decimals cannot be written exactly in finite digits, so the cutoff is stated honestly.
Frequently Asked Questions
Why does my phone calculator show 0.30000000000000004?
Binary floating-point cannot represent 0.1 exactly. This tool avoids floats entirely for exact decimal results.
How many decimal places does division show?
12, rounded. Addition, subtraction and multiplication are fully exact.
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