Adding and subtracting fractions needs a common denominator; multiplying and dividing do not. That single difference is where most mistakes start. This calculator does the arithmetic exactly, using whole numbers throughout, so the answer is a true fraction rather than a rounded decimal dressed up as one.

Using it in three steps

1. 1 Type the first fraction: the numerator above the line, the denominator below it.
2. 2 Pick the operation in the middle, then type the second fraction the same way.
3. 3 Read the answer in whichever form your work needs - simplified fraction, mixed number or decimal.

Why the answer is simplified

2/4 and 1/2 are the same number, but only one of them is the finished answer. Simplifying divides the top and bottom by their greatest common factor, which is why 6/8 becomes 3/4 and not 12/16. The sign is also moved to the top, so a negative fraction always looks the same rather than hiding a minus in the denominator.

Mixed numbers and decimals

A mixed number splits the fraction into a whole part and a remainder, which is easier to picture when measuring: 7/3 of a metre means little until you read it as 2 metres and a third. The decimal is the same value again, but it can only be approximate when the fraction repeats - 1/3 is exactly one third, while 0.3333 is not.