ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

How to Add a Fraction With a Different Denominator

Updated on November 4, 2014

With Different Denominators the Process is Just a Little Different

All fractions consist of two parts, a top part, which is called the numerator and the bottom part, which is called the denominator. Thus we have:

Numerator / Denominator

If both fractions to be added have the same denominator the process is simple – simply add the two numerators and use the same denominator that both share as follows:

1/3 + 1/3 = 2/3

When the denominators are different, we have to make an adjustment, as we can only add two or more fractions if all have the same denominator.

What is the Least Common Denominator and How to Find It

If we want to add 2/3 plus 1/2 we have to first find a common denominator that both can use.

A common denominator is a number that can be evenly divided by the denominators of both fractions.

While, sixty is a number that can be evenly divided by both denominators, it is better to find the smallest number that can be evenly divided by each.

This is called the least common denominator.

In this case, 6 is a number that can be evenly divided by both 3 and 2.

Since there is no smaller number that can be divided evenly by both 3 and 2, 6 is the least common denominator.

Using the Least Common Denominator

The rule here is to divide the least common denominator by each denominator and then multiply that denominator's numerator by the result.

For instance, with 6 as the new common denominator, first divide 6 by the 3 in 2/3 and get 2 as the result.

Then multiply the numerator of 2 in 2/3 by the result, which in this case is also 2 to get 4/6 as the new fraction.

Doing the same with 1/2 we divide 6 by the denominator 2 to get a result of 3 and then multiply the 1 in 1/2 by the result of 3 to get 3/6 as the new fraction.

We now have two fractions with the same denominator of 6, so we add them as follows:

4/6 + 3/6 = 7/6

Cooking and Knowing How to Add Fractions

Now, the question is, other than writing articles for HubPages, of what practical use is this this process of adding fractions?

Well, cooking is one area where this can come in handy, especially when you want to increase a recipe.

If you are having company over for dinner and the recipe for the dish you want to serve will prepare enough to feed four people but you will be serving six people, you will have to increase each of the the ingredients in the recipe.

In this case, you will be increasing the number of people being served by 2. Since two is one-half of the four servings the recipe will make you will have to increase each ingredient by one-half.

Examples of Adding Fractions in Recipe Calculations

Thus, where the recipe calls for 2/3 cup of water you will have to add 2/3 plus half again as much or 1/3. Since, in this case the denominators are the same the process of adding the two is relatively easy.

To calculate the amount of water needed for a six serving batch you will have to add:

2/3 cup + 1/3 cup = 3/3 cup = 1 cup of water

When we divide the 3 in the numerator by the 3 in the denominator we get 1.

However, where the recipe calls for 1/2 teaspoon of salt you will have to add 1/4 teaspoon to the 1/2 teaspoon to that to get the amount needed for six people.

In this case we have to find the least common denominator for the two fractions, which turns out to be 4.

Dividing the 2 in the denominator of 1/2 into the least common denominator which is 4, we get 2. Two times the numerator of 1 in the fraction 1/2 gives us 2 or 2/4 as the new fraction using the least common denominator.

2/4 teaspoon + 1/4 teaspoon = 3/4 teaspoon

For our six person recipe we will need 3/4 teaspoon of salt.

What Will You Use Calculating Fractions For?

For high school students, a knowledge of how to add fractions is a chore to be learned in order to pass the tests in math so they can move on to the next grade and eventually graduate.

However, many math skills learned in high school will come in useful not only in some jobs but also in every day life.

Did you find this Hub helpful for school or some practical problem in life?

See results

© 2006 Chuck Nugent


    0 of 8192 characters used
    Post Comment

    • profile image


      7 years ago

      it did not help

    • profile image


      7 years ago

      sorta hard

    • profile image


      8 years ago

      Yo this website explains every easily now i totally understand

    • profile image


      8 years ago

      okay ,, now ! i understand how to add the fractions ...

      now i understand more than yesterday !!!

    • profile image


      8 years ago

      Wow, the only page on the internet that actually explains it simply. Thanks!!

    • profile image

      asiatu mattia 

      8 years ago

      all the math programs are especially beneficial for those of us that have forgotten our math facts and have kids in school .i am especially grateful. cant do without math helper.keep it up!!!!!!!!!!!!!!

    • profile image


      8 years ago

      really2 super easy...that's why...

    • profile image


      8 years ago

      this is so easy

    • profile image


      9 years ago

      adding with different denominators

    • profile image


      9 years ago

      i want u to ask me some addition of fractions pls

    • profile image

      Jose De La Rosa 

      9 years ago

      Thanks!! Easy to understand

    • profile image


      9 years ago


    • profile image


      10 years ago

      this is horrible!!! we know this so u should just take this off the internet

    • profile image


      10 years ago

      did not understand!!

    • profile image


      11 years ago

      i guess this was a good website cuz this is the only one i really understood out of all umm lets say 10 pgs. i researched on how to add fractions with unlike denominators. thanks!!!!


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)