Fraction Calculator
Four operations on two fractions, with the reduced result and the steps that got there.
Fraction Calculator
Why Fractions Trip People Up
Almost every fraction mistake is a missing common denominator. Multiplying and dividing do not need one, which makes it easy to forget that adding and subtracting absolutely do. Two thirds plus one quarter is not three sevenths, and the calculator above shows why by rewriting both parts over twelve before it adds anything.
The second common slip is stopping too early. An answer of eight twelfths is correct but unfinished, and in most classrooms it loses a mark. Anything this page returns is already reduced as far as it goes.
Adding and Subtracting
Find a denominator both fractions can use, rewrite each one over it, then work only on the top numbers. The bottom stays put. For 2/3 + 1/4 the shared denominator is 12, the fractions become 8/12 and 3/12, and the answer is 11/12, which will not reduce.
Subtraction behaves identically until the result goes negative, which is allowed and simply carries the sign on the numerator.
Multiplying and Dividing
Multiplication is the straightforward one: tops together, bottoms together, reduce. 2/3 times 4/5 is 8/15.
Division flips the second fraction and then multiplies. 2/3 divided by 4/5 becomes 2/3 times 5/4, which is 10/12, reducing to 5/6. Flipping the wrong fraction is the classic error here, so the steps above always name which one was inverted.
Mixed Numbers
A mixed number like 2 1/3 is converted to 7/3 before any arithmetic happens, because improper fractions are far easier to compute with. The result is given back in both forms so you can quote whichever your teacher expects.