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Math for Kids23 chapters | 325 lessons

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Instructor:
*Emily Hume*

Emily is a Reading Specialist and Literacy coach in a public elementary school with a Master's Degree in Elementary Education.

Math is more than just whole numbers; sometimes you will only have a part of a whole, known as a fraction. And sometimes, you can even have a whole and a fraction together. In this lesson, you will learn what compound fractions are and how to add them together.

It's your birthday! Dad cuts a big piece of cake for you, and one for himself. You gobble yours down and then eat half of your dad's piece! Did you know you have just gobbled down a **compound fraction**? When you have a number such as 1 1/2, which contains a whole number (such as 1) along with a fraction (1/2), you have a compound fraction, which is frequently called a **mixed number.**

You take cupcakes to class for your birthday. After your party, you have 1 1/2 chocolate and 2 1/2 vanilla left. So, how many cupcakes do you have left in all? You have to add compound fractions to find out! Here are the steps:

1. Put the whole numbers together and the fractions together, with a plus sign in between (See image: Cupcake Mixed Numbers!)

2. Add the whole numbers together: 1 + 2 = 3. Then add the fractions together: 1/2 + 1/2 = 2/2, or 1 whole. (Reminder: When adding fractions, only add the top numbers - the bottom number stays the same!) Add the 3 and the 1 and you have 4 total cupcakes left over!

Because your denominators, or bottom numbers, were the same in your cupcake fractions, adding these fractions was easy! That won't always be the case. Sometimes you will have to find a **common denominator**, a number that both denominators divide evenly into.

For example, suppose you had 1 1/4 chocolate and 2 1/8 vanilla cupcakes left. The first step is the same: add the whole numbers 1 + 2 = 3. Then you need to find a way to add 1/4 and 1/8. 8 can be divided by 4 *and* by 8, so it's a good number to use as a common denominator.

To change 1/4, put the 8 on the bottom and divide by 4 (=2). Then take that number and multiply by the top number (2 x 1 = 2). So, 1/4 = 2/8. 2/8 + 1/8 = 3/8. Altogether, you had 3 3/8 total cupcakes leftover.

For more information about finding common denominators and adding fractions with unlike denominators, see the lesson How to Add Fractions with Unlike Denominators.

In adding the compound fractions this way, you may end up with a number that is more than a whole (more than 1). For example: 1 3/8 + 2 7/8.

First, add 1 + 2 = 3

Then, add 3/8 + 7/8 = 10/8. This fraction needs to be simplified. Divide the numerator (10) by the denominator (8) and you get 1 with 2 left over. This is written as 1 and 2/8. Next you must reduce the fraction, which, in this case, you do by dividing both the top and bottom number by 2, giving you 1/4 (2 divided by 2 = 1, 8 divided by 2 = 5).

So, you have the 3 plus the 1 1/4 and you get 4 1/4!

A **compound fraction**, also known as a **mixed number**, consists of a whole number with a fraction. In order to add them together, you must first add the whole numbers . Then, you must make sure the **denominators**, or bottom numbers, in the fractions match. If not, find the common denominator and finally, you can add your fractions together.

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Math for Kids23 chapters | 325 lessons

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- Comparing Fractions: Lesson for Kids
- Equivalent Fractions: Lesson for Kids
- How to Add Fractions: Lesson for Kids
- Fractions Games for Kids
- Fractions to Decimals: Lesson for Kids
- Fractions: Lesson for Kids
- Numerator & Denominator Lesson for Kids
- Decimals: Lesson for Kids
- Multiplying Fractions by Whole Numbers: Lesson for Kids 3:04
- How to Simplify Fractions: Lesson for Kids
- Improper Fractions: Lesson for Kids
- What is a Benchmark Fraction on a Number Line? 3:48
- How to Add Mixed Fractions with Different Denominators
- Multiplying Compound Fractions
- Simplifying Compound Fractions
- Dividing Compound Fractions
- Adding Compound Fractions
- How to Subtract Fractions with Variables
- Multiplying Fractions with Like Denominators
- Subtracting Fractions with Like Denominators
- Reducing Fractions: Rules & Practice
- Definition of Simplest Form: Lesson for Kids
- How to Add Fractions with Unlike Denominators
- How to Subtract Fractions with Unlike Denominators
- Rules for Subtracting Fractions
- Rules for Multiplying Fractions
- Rules for Dividing Fractions
- Ordering Fractions on a Number Line
- Locating Fractions on a Number Line
- How to Add & Subtract Two Fractions with Like Denominators
- How to Find Equivalent Fractions on a Number Line
- How to Subtract Mixed Fractions with Unlike Denominators
- Go to Fractions for Elementary School

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