Algebra and Pre-Algebra Lessons

Algebra 1 | Pre-Algebra | Practice Tests | Algebra Readiness Test

Algebra E-Course and Homework Information

Algebra E-course Info | Log In to Algebra E-course | Homework Calculator

Formulas and Cheat Sheets

Formulas | Algebra Cheat Sheets
» » Adding Fractions

Adding Fractions with Unlike Denominators

Many people have difficulty adding fractions with unlike denominators. There's no doubt that fractions are difficult to deal with especially when you have to find the least common denominator.

I'm going to show you three examples, and I will break down each step for you. By following my examples, step by step, you will quickly learn how to add fractions with unlike denominators. If you are really struggling, be sure to check out the video examples.

In order to be successful with this lesson, you must be comfortable with finding the least common multiple and writing equivalent fractions. Please go back and review these lessons if you are not proficient with these two skills.

OK.. Here we go with Example 1. We'll start with the video lesson and the written lesson will follow.

Example 1

youtube channel If you want to see this example on video, click here to visit my You Tube channel.

adding fractions with unlike denominators
adding fractions

So, let's recap.

Steps for Adding Fractions with Unlike Denominators

1. Identify the least common denominator by finding the least common multiple for the denominators.

2. Write equivalent fractions (making sure that each equivalent fraction contains the least common denominator (LCM))

3. Add the equivalent fractions that you wrote in step 2. (The denominators should now be the same.)

4. Simplify if necessary.

Example 1 was written horizontally, which I'm finding more people are doing lately. I still favor adding fractions that are written vertically which you will see in Example 2.

For Example 2, we will add fractions where neither denominator is the least common denominator. But, we'll still follow the same steps. Take a look....

Example 2

adding fractions with unlike denominators
how to add fractions

Having Trouble? Watch this example on video.

youtube channel If you want to see this example on video, click here to visit my You Tube channel.

Special Note

These lessons focus on finding the least common denominator because this will make simplifying at the end much easier. If you cannot figure out the "least common denominator", you can use any common denominator; however you will have to simplify at the end.

Hint: You can always find a common denominator by multiplying the denominators together.

I do recommend finding the least common denominator if possible, but don't fret if you can't! You will still be able to complete the problem.

Ok,let's step it up a little. For the last example, we will add 3 fractions. Calm down..... this is a piece of cake! We'll use exactly the same process. Take a look...

Example 3

adding fractions
adding fractions

Do you feel a little better about adding fractions with unlike denominators? I hope so! If you are feeling pretty good, then the great news is that if you can add fractions, then you can also subtract fractions. The same process is used, you will only subtract the numerators instead of adding the numerators.

Your next Pre-Algebra Lesson is Subtracting Fractions with Unlike Denominators

Like This Page?


We would love to hear what you have to say about this page!

Other Fraction Pages You Might Like

Top of the Page

Follow Algebra-Class

Recommend Algebra Class

Algebra Class E-course Members


Sign Up for Algebra Class E-courses

Click here to retrieve a lost password.

Search This Site

Custom Search

Having Trouble with Your Homework?


Algebra Class Courses

algebra ecourse

algebra 1 review course

pre algebra ecourse

Algebra Class
Most Popular Pages

algebra practice test

algebra cheat sheets

algebra formulas

What People Are Saying...

"I'd like to start off by relaying my sincerest gratitude for your dedication in teaching algebra. Your methodology is by far the simplest to follow, primarily because you take the time to include the small steps in between that most other teachers leave out.

It helps to know why you are doing something. I am 45 and heading to college to get my BS in Business. I need to brush up, hence the visit to your site. Great Job!"

Jimmy - United States

"I stumbled onto your site after I found out that I needed to use some fundamental algebra for an assignment. Turns out I had forgotten some things and your great site helped me remember them like "that" (snap of fingers). The organization of the site let me find exactly what I was looking for so easily. Kudos to you for maintaining such a great resource for students of all ages!"

Tom - United States

"I just wanted to write and basically thank you for making such a wonderful website! I'm 20 years old and about to take a basic placement test for college. I wanted to brush up on my Algebra skills and I stumbled upon your site. I'm amazed at how simple you make it and how fast I'm remembering Algebra! I don't remember getting most of the answers right when I had an actual teacher in front of me teaching this. Thanks a lot!"

Elizabeth - United States

"I am a pensioner living in South Africa. I stumbled on your website, the best thing that could ever happen to me! Your course in Algebra has helped me a lot to better understand the different concepts. Thank you very much for sharing your skills for teaching math to even people like me. Please do not stop, as I am sure that your teachings have helped thousands of people like me all over the world."

Noel - South Africa

This is an amazing program. In one weekend I used it to teach my Grade 9 daughter most of the introductory topics in Linear Relations. I took her up to Rate of Change and now she can do her homework by herself.

Reg - United States

Helpful Resources



More Algebra Resources


Subscribe To This Site

Add to Google
Add to My Yahoo!
Add to My MSN
Add to Newsgator
Subscribe with Bloglines

Enjoy This Site?
Then why not use the button below, to add us to your favorite bookmarking service?

Connect and Follow Algebra Class

Copyright © 2009-2014 Karin Hutchinson ALL RIGHTS RESERVED