# Proportions

Imagine that you have a great recipe for cheese dip but it only serves four people. You are having a party and twenty people will be at the party. How can you adjust a recipe that serves four people so that it will serve twenty people? This is one example on how proportions can be used to solve everyday problems.

## What are proportions?

A proportion is a math equation that demonstrates that two ratios are equivalent. Understanding what a proportion is can help you find missing values in a math problem. Proportions can help people increase a cheese dip recipe in order to feed a large group of people at a party. They are used to enlarging or reduce the sizes of pictures and a variety of other things. Proportions are usually written as equivalent ratios (fractions). They can be represented in tables and graphs as well.

Examples of proportions ## Tests for proportions

Ratios can be tested to see if they form proportions.

1. You can use a common denominator if the ratios are written as fractions.
2. You can check to see if the cross products are the same if the ratios are written as fractions.
3. You can determine if the ratios are equivalent if they are changed to decimals.

## Types of Proportion Problems

Here are some examples of proportion problems that you might see in middle school math. ## Proportion Tables

Proportions are better understood if the numbers are written in tables. Look at these tables. Take notice of patterns in each table and the similarities of the tables.  