How do you sum unlike fractions?

Answer 1

Step 1: Find a common multiple of the two denominators. The least common multiple is preferable, but not an absolute necessity.

Step 2a: Take the first fraction and find an equivalent fraction with this common multiple as its denominator.

Step 2b: Do the same for the second fraction.

Step 3: Add the numerators of these equivalent fraction and this will be the numerator of the sum. The denominator of the sum will be the common multiple.

Step 4: Simplify the answer if possible. If you have gone for a common multiple rather than the lowest common multiple, this will always be possible.

Step 5: Enjoy.

So here is an example:

2/3 + 5/7

Step 1: The two denominators are 3 and 7. LCM(3, 7) = 21

Step 2a: 2/3 = 14/21

Step 2b: 5/7 = 15/21

Step 3: Numerator = 14+15 = 29. Denominator = 21. So answer = 29/21

Step 4: Cannot be simplified.

Step 5: Oh, yesss!