Fraction Calculator
Two fractions, one operation, reduced to lowest terms. Click any i for detail.
Fractions
First numerator
i
Numerator
Top of the first fraction. |
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|---|---|
First denominator
i
Denominator
Must be non-zero. |
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Operation
i
Op
Add, subtract, multiply, or divide. |
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Second numerator
i
Numerator
Top of the second fraction. |
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Second denominator
i
Denominator
Bottom of the second fraction. |
How to use this calculator
- Enter numerator and denominator for both fractions.
- Pick add, subtract, multiply, or divide.
- Read the reduced result and decimal.
- Convert mixed numbers to improper fractions first.
Results explained
Addition and subtraction use a common denominator. Multiplication multiplies tops and bottoms. Division multiplies by the reciprocal. Results reduce by GCD.
Quick reference: fraction ops
1/2 + 1/3 needs denominator 6.
| Item | Detail |
|---|---|
| Add/subtract | (ad ± bc) / bd |
| Multiply | ac / bd |
| Divide | ad / bc |
| Reduce | divide top and bottom by gcd |
Mixed numbers like 1 1/2 should become 3/2 before you calculate.
How the estimate is built
a/b ± c/d = (ad ± bc)/bd; a/b × c/d = ac/bd; a/b ÷ c/d = ad/bc; reduce by gcd.
Example scenario
1/2 + 1/3 → 5/6 (≈ 0.833).
FAQ
How do I enter 1 1/2?
Convert to 3/2: multiply the whole number by the denominator, add the numerator.
Why is divide upside down?
Dividing by c/d is the same as multiplying by d/c.
Does this do percent off?
No. Percent markdown is a money page, not fraction arithmetic.