Compare Fractions with Related Denominators

In this activity, we will learn how to compare fractions whose denominators are all multiples of the same number.

We will not be converting the fractions to decimals, but will use the idea of equivalent fractions.

Remember, multiply or divide the numerator (top number) and the denominator (bottom number) of a fraction by the same number to change it to an equivalent fraction.

Example

Is the following comparison true or false? 

Answer

We look for the smallest number that 6 and 9 both go into.

This is called a common multiple.

This will be 18, so we change both fractions into 18ths.

We multiply the numerator and denominator of 4/6 by 3:

We multiply the numerator and denominator of 7/9 by 2:

Now we can compare the equivalent fractions. 

So the first statement was false.

It should be written like this.

Now it's time to try some of these by yourself.