About this calculator
The Adding Fractions Calculator adds two to five fractions and shows the LCD, equivalent fraction conversion, numerator addition, and simplification. It is designed for homework-style addition with unlike denominators.
adding fractions calculator method
To add fractions with unlike denominators, convert each fraction to the least common denominator, add the numerators, then simplify.
- LCD = LCM of denominators
- a/b = (a x LCD/b) / LCD
- sum = converted numerators / LCD
How to use the adding fractions calculator
- Enter at least two fractions.
- Add up to five fractions if needed.
- Find the LCD of all denominators.
- Convert every fraction to the LCD.
- Add the converted numerators.
- Simplify the final answer.
Worked examples
Two unlike denominators
Input: 1/3 + 1/4
Calculation: LCD = 12; 4/12 + 3/12
Result: 7/12
Three fractions
Input: 1/2 + 1/3 + 1/6
Calculation: LCD = 6; 3/6 + 2/6 + 1/6
Result: 1
Adding same denominators
When denominators are already the same, add the numerators and keep the denominator.
Adding unlike denominators
When denominators differ, convert to equivalent fractions with the LCD before adding.
Learning and homework note
This calculator is for learning, checking, and general educational use. It shows the method so students can compare each step with their own working, but it should not replace learning the underlying fraction rules.
- Check that every denominator is not zero.
- Negative fractions can be written in more than one equivalent form.
- Rounding may affect decimal or percentage displays.
Frequently asked questions
Does this show the working?
Yes. The fraction calculators are designed to show the main steps, not just the final answer.
Does it simplify answers?
Yes. Fraction answers are reduced to lowest terms where simplification is part of the method.
Can denominators be zero?
No. A denominator of zero is undefined in fraction arithmetic.
Can I use negative fractions?
Yes, but pay attention to signs. The calculator normalises signs so the denominator stays positive.
Why might my teacher write the answer differently?
Equivalent fractions and mixed numbers can represent the same value. Check whether the question asks for improper fraction, mixed number, decimal, or simplest form.
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- Fraction Calculator
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- Simplify Fractions Calculator