Basic Math and Pre-Algebra For Dummies, 2nd Edition

Chapter 12

Playing with Percents

In This Chapter

Understanding what percents are

Converting percents back and forth between decimals and fractions

Solving both simple and difficult percent problems

Using equations to solve three different types of percent problems

Like whole numbers and decimals, percents are a way to talk about parts of a whole. The word percent means “out of 100.” So if you have 50% of something, you have 50 out of 100. If you have 25% of it, you have 25 out of 100. Of course, if you have 100% of anything, you have all of it.

In this chapter, I show you how to work with percents. Because percents resemble decimals, I first show you how to convert numbers back and forth between percents and decimals. No worries — this switch is easy to do. Next, I show you how to convert back and forth between percents and fractions — also not too bad. When you understand how conversions work, I show you the three basic types of percent problems, plus a method that makes the problems simple.

Making Sense of Percents

The word percent literally means “for 100,” but in practice, it ...