Comparing Fractions By: Ms. J. Godfrey

Comparing Fractions  When you compare fractions, you use symbols. > greater than < less than = equal to

How to compare fractions  There are three methods that you can use to compare fractions.  Method 1: Cross multiplication  Method 2: Common denominator  Method 3: Changing the fractions to decimals then comparing the decimals. (previously taught)

Method 1: Cross multiplication (5) ____ 5 Step 1: Multiply the numerator of fraction 1 by the dominator of fraction 2. 1 x 5 = 5 * Place the product above the 1 st fraction.

Method 1: Cross multiplication (5) (4) ____ 5 Step 2: Multiply the numerator of fraction 2 by the dominator of fraction 1. 2 x 2 = 4 * Place the product above the 2 nd fraction.

Method 1: Cross multiplication (5) (4) These are your products ___ 5 Step 3: Compare the products by placing a symbol in the middle. *Make sure you read from left to right. 5 is _____ 4 What is the correct answer? a) c) =

Method 2: Common Denominator ___ 6 Step 1: Find the least common denominator of the given fractions. Denominators: 4 and 6 See next slide for steps to find LCD.

Method 2: Common Denominator How to find the least common denominator: 4 x 1 = 4 6 x 1 = 6 4 x 2 = 8 6 x 2 = 12 4 x 3 = 12 6 x 3 = 18 4 x 4 = 16 6 x 4 = 24 LCD: 12

Method 2: Common Denominator Step 2: Compose equivalent fractions that will have the LCD. 3= ___ 3 x 3 = x = ___ 2 x 2 = x 2 12 * When composing equivalent fractions, you must divide the numerator and denominator by the same number.

Method 2: Common Denominator Step 3: Compare the new fractions by looking at the numerator. * Make sure to put them back in the order that they were given _>_ 12 so _>_ 6