Fractions are simple once you remember the rules. This calculator does the working for you and shows every step, so you can check your homework and learn the method.
How to use the fraction calculator
- Enter the numerator (top) and denominator (bottom) of the first fraction.
- Choose the operation: +, −, × or ÷.
- Enter the second fraction.
For a whole number, use a denominator of 1 (for example, 3 = 3/1). For a negative fraction, put the minus sign on the numerator.
Rules
Add or subtract: rewrite both fractions with the LCM of b and d as the denominator, then add or subtract the tops
a/b × c/d = (a × c) / (b × d)
a/b ÷ c/d = a/b × d/cFinally, divide the top and bottom by their HCF to get the simplest form.
Examples
- 1/2 + 1/3 = 3/6 + 2/6 = 5/6 (0.833333)
- 5/6 − 1/4 = 10/12 − 3/12 = 7/12
- 3/4 × 2/5 = 6/20 = 3/10
- 2/3 ÷ 4/9 = 2/3 × 9/4 = 18/12 = 3/2 = 1 1/2
FAQ
What is a mixed number?
A whole number and a fraction together, like 1 1/2. An improper fraction such as 3/2 can be written as a mixed number by dividing: 3 ÷ 2 = 1 remainder 1, so 1 1/2.
How do I find a common denominator?
Use the LCM of the denominators. The LCM and HCF calculator finds it for any set of numbers.
How do I convert a fraction to a decimal?
Divide the top by the bottom, or use the decimal to fraction calculator, which works both ways.