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# PERCENTAGES: PERCENTAGES IN CONTEXT

This guide uses multiple ways to convert decimals and fractions into percentages. In addition, this guides uses a uniform proportion set up that can be used with any type of percentage calculation that contains a whole and a part.

## INTRODUCTION

From recipes to engineering, conversions and percentages are extremely useful for everyday tasks. The uniform proportion set up used in this LibGuide can help anyone calculate a whole, part, or percentage in a variety of applications.

## OUR GOAL

Our goal is to calculate a percent, part, or whole of any given scenario. The percent will usually have a percent sign next to the number. The whole is the total amount of people or other quantities surveyed or collected.

In a given scenario, one piece of information will be unknown, therefore, this gives us a clue to what information is known.

There are 3 possible scenarios:

1. There is no percent given, which means we have a part of the total and a whole/total.
2. There is no part given, which means we have a percent and a whole/total amount.
3. There is no whole or total amount given, which means we have a percent and a part of the total.

## PROPORTION IN ACTION!

Check out this video to see proportion in action!

## WHAT CAN WE USE TO CALCULATE THE MISSING INFORMATION? We can use this proportion set up with cross multiplication to solve any scenario falling in the 3 scenarios mentioned.

## WHAT IS A PART OR A WHOLE?

A part will always be a piece of the total amount of a quantity in a given scenario. If the percent given is smaller than 100%, then they number will be smaller than the total.

A whole will always be the total amount of a quantity in a given scenario. This number is the 100% amount, which is why the 100 in the proportion given above never changes.

Check out this scenario:

In a scenario, the part will be a piece of the whole. For example, there were 21 students in CUL 122, but only 18 showed to class.

18 out of 21 students.

18 is the part and 21 is the whole.