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# Lesson 5 — Activity 1: Working with Fractions with Like Denominators

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# Lesson 5 — Activity 1: Working with Fractions with Like Denominators

#### Getting Ready

#### Fractions are used in many daily activities and expressions. For example, you might say that it is half an hour until the bell rings, or that there are three quarters of a pizza left. These are both fractions.

#### You may remember from previous courses that there are three main types of fractions: proper, improper, and mixed.

#### A proper fraction is a fraction that expresses a number between 0 and 1. You can easily identify a proper fraction. In a proper fraction, the numerator is SMALLER than the denominator.

#### The following are all examples of proper fractions:

#### Notice that all of the above fractions have numerators that are smaller than their denominators — their "tops" are smaller than their "bottoms"!

#### An improper fraction is a fraction that expresses a number that is 1 or larger than 1.

#### Again, it is fairly easy to identify an improper fraction since in an improper fraction, the numerator is THE SAME AS or LARGER than the denominator.

#### The following are all examples of improper fractions:

#### All of the above fractions have numerators that are the same size or larger than their denominators — their "tops" are the same size or larger than their "bottoms".

#### A mixed number is made up of a whole number and a proper fraction.

#### Mixed numbers, like improper fractions, also express a number that is 1
or larger than 1.

#### The following are all examples of mixed numbers:

#### It is important to remember that since improper fractions and mixed numbers express the same thing, they can be converted from one to the other.

#### Try This:

Click here to practise identifying fractions. You can identify both proper fractions and mixed numbers. Start with any level you'd like. Try to complete at least three levels.

#### There may be times when you want to add or subtract fractions.

Here's an example:

Fay made two pies for a picnic. 2/8 of her apple pie and 3/8 of her cherry pie were left. How much pie in total did she take home?

## In order to add or subtract fractions, you must have a common denominator.## For example, if you wished to solved the pie problem, you would do this:
## This drawing shows how you would show the equation in a picture format.
## Fay took home 5/8 pie in total. (You should always write a statement to complete a problem.) |

#### Try This:

#### Here is a subtraction problem for you to solve.

#### Over
the weekend, Jon drank 4/5 of a bottle of soda and Kris drank 1/5
of a bottle. How much more soda did Jon drink than Kris? (Don't forget your statement.)

#### 4/5 – 1/5 = 3/5

#### Jon drank 3/5 more soda than Kris.

## Sometimes you have to work with mixed numbers in order to solve a problem.## For example, you want to double a recipe for chocolate chip cookies. The original recipe calls for 2 1/3 cups of flour. |

#### Solutions for fraction problems should be shown in their lowest form or smallest equivalent fraction.

#### You can reduce fractions to their lowest form by:

- dividing

- using greatest common factors

#### Here's an example:

Les baked 48 cookies for the bake sale at school and sold 36 of them. In fraction form, how many cookies did Les sell?

Les sold 36/48 cookies.

#### Go to Tab 1 to see how to reduce this fraction using division.

Go to Tab 2 to see how to reduce this fraction using greatest common factor.

#### Find a number that can be divided into both the numerator and denominator. Divide, then repeat until the numerator and denominator cannot be divided further.

#### 3/4 is the lowest form of 36/48.

- Identify factors and the greatest common factor (GCF) of the two numbers.

The set of factors for 36 is:

36: {1, 2, 3, 4, 6, 9, **12**, 18, 36}

The set of factors for 48 is:

48: {1, 2, 3, 4, 6, 8, **12**, 16, 24, 48}

The GCF of 36 and 48 is **12**.

##### Divide

#### Again, it is shown that 3/4 is the lowest form of 36/48.

- Identify factors and the greatest common factor (GCF) of the two numbers.

The set of factors for 36 is:

36: {1, 2, 3, 4, 6, 9, **12**, 18, 36}

The set of factors for 48 is:

48: {1, 2, 3, 4, 6, 8, **12**, 16, 24, 48}

The GCF of 36 and 48 is **12**.

##### Divide