# Lesson 15 Common Denominators to Compare

• Let’s compare fractions by writing equivalent fractions with the same denominator.

## Warm-up What Do You Know About …?

What do you know about 15 and 30?

## Problem 1

In each pair of fractions, which fraction is greater? Explain or show your reasoning.

1. or

2. or

## Problem 2

Han says he can compare and by writing an equivalent fraction for . He says he can’t use that strategy to compare and . Do you agree? Explain your reasoning.

## Problem 3

Priya and Lin showed different ways for comparing and . Make sense of what they did. How are their strategies alike? How are they different?

Priya:

​​ is greater than , so ​​​​​ is greater than .

Lin:

is greater than , so is greater than .

## Problem 1

For each pair of fractions, write a pair of equivalent fractions with a common denominator.

1. and

2. and

3. and

4. and

## Problem 2

For each pair of fractions, decide which fraction is greater. Be prepared to explain your reasoning.

1. or

2. or

3. or

4. or

## Problem 1

1. List these fractions from least to greatest.

2. Explain or show your reasoning.