General Math On-line

 Chapter 3 Percents Overview

 What will I be able to do when I finish this chapter?

Convert between fractions, decimals, and percents.

Calculate three types of percent problems.

Determine percent increase and decrease.

Solve application problems.

 

Chapter 3 Tips and Hints:

Percents are like decimals and fractions. They help you express a number that is less than a whole. The word percent actually means "parts per 100". For example, if a store is having a "25% Off Sale", you will get a discount of 25 dollars for every 100 dollars you spend.

25% = 25/100 = 0.25

When converting between percents, decimals, and fractions, it can help to have a model to follow. Write down a simple conversion like the one below and you can follow the same pattern to convert any problem. 1/2 = 0.50 = 50%

 

The method used for solving percent problems in the textbook is very useful for a number of reasons.

You can use the same set-up to solve any type of percent problem.

You don't have to worry about converting the percent to a decimal.

It is based on proportions, which is an important skill you will use in future chapters.

 

The section on Percent Increase and Decrease can be tricky because there are a number of ways to phrase these types of problems. You will be successful with these problems if you remember two things. First, the part is always the change (the increase or decrease). Second, the base is always the original conditions.

An old machine could produce 350 widgets per day. The new machine can produce 550 widgets per day. What is the percent increase in production?

In this problem, the part is 200 (the increase). The base is 350 (the original condition). 

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