How to Add Fractions With Unlike Denominators

Calculating how to add fractions with unlike denominators can be challenging. If you are willing to follow these simple steps you will be able to achieve success in completing this daunting task. Many times people will see this on a test, during homework or simply while doing home improvements and will not be able to finish the task.

Instructions

Calculate Fractions with Unlike Denominators

1. Get yourself a couple of fractions that you would like to combine to see what they will add to. Use two different fractions that will have different denominators or the number that is in the lower half of the fraction. Fractions such as 2/5 and 1/3 are good examples.

2. Try to determine what the least common denominator of these two fractions is. To determine what the least common denominator of fractions is you will need to least the factors of the denominators. In the case of 2/5 the factors are 5, 10, 15, 20 and 25, while the factors of 2/3 are 3, 6, 9, 12, 15, 18 and 21. You will then compare the lists that you have made and find a match between the two, which in this example is 15.

3. Multiply the fractions in order to create the least common denominator. When you do this you will use the factor that got the number 15 for both of the fractions. You will multiply 2/5 times 3/3 and will then come up to 6/15 then you will multiply 1/3 times 5/5 and will arrive at 5/15. Now you have the equivalent of the fractions you started with, but with denominators that are the same.

4. Having common denominators allows you to add the fractions together. With the fractions, having the same denominator you will only add the numerators or top numbers together to get your new combined fraction. Here we will add 6/15 with 5/15 to get the answer of 11/15.