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 - Adding fractions with unlike denominators
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
Having trouble? Watch this example on video.
These lessons focus on finding the least common denominator
because this will make simplifying at the end much easier.
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
Ok,let's step it up a little. For the last example, we will add 3
Calm down..... this is a piece of cake! We'll use exactly
the same process. Take a look...
Example 3 - Adding three 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
The same process is used, you will only subtract the
numerators instead of adding the numerators.
Your next faction lesson is Subtracting Fractions with Unlike Denominators.
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