Adding and Subtracting Fractions
Add and subtract fractions with unlike denominators step by step. Free online fraction calculator computes a/b + c/d or a/b - c/d with simplified results and decimal conversion.
About This Calculator
This calculator adds or subtracts two fractions with step-by-step simplification. For a/b + c/d, it computes (ad + bc)/bd. For a/b - c/d, it computes (ad - bc)/bd. The result is simplified by dividing numerator and denominator by their greatest common divisor.
Fraction arithmetic is fundamental in mathematics, cooking (recipe scaling), construction (measurements), and everyday calculations involving parts of a whole.
Frequently Asked Questions
How do you add fractions with different denominators?
Find the common denominator (product of both denominators), convert each fraction, then add the numerators. For a/b + c/d = (ad + bc) / bd. Then simplify by dividing by the GCD.
How do you subtract fractions?
Follow the same process as addition but subtract the numerators: a/b - c/d = (ad - bc) / bd. Find the common denominator, convert, subtract, and simplify.
What is the common denominator method?
The common denominator is a number that both denominators divide evenly. The simplest common denominator is the product of both denominators. Use it to rewrite both fractions with the same denominator before adding or subtracting numerators.
Do I need to simplify the result?
Yes, fraction results should always be simplified to lowest terms by dividing numerator and denominator by their greatest common divisor (GCD). The calculator does this automatically.
What if the denominators are the same?
If denominators are already the same, simply add or subtract the numerators and keep the common denominator. For example, 3/7 + 2/7 = 5/7. The calculator handles this correctly.
Is this tool free?
Yes, all calculators on Calculy are completely free to use with no registration required.