Title: The Basics: Percents
Course: Open PRO130 Instrumentation I

 | The Basics: What Do We Mean by Percent?

The word percent means "out of 100."   "Per" means "out of" and "cent" comes from the Latin word centum meaning 100.   Since percent means "out of 100" we can write:   n% =

When solving equations with percents, you need to turn a percent into a decimal.  You do this by removing the percent sign and moving the decimal point two places to the left.

When solving for percent, answers need to be converted into percents by moving the decimal point two places to the right.   This is the same thing as multiplying the number times 100.

The formula used to find percent, base or amount is:   or

The word "of" means multiplication and you can use that word to help you identify the number that is the base because it comes right after the word "of".

The number that is the amount (or part of 100) can be identified because it comes after the word "is."   "Is" means "equals" in this math.

Watch these helpful Khan Academy videos for more information:

1.  Describing the Meaning of Percent

2. Describing the Meaning of Percent 2

3.  Representing a number as a decimal, percent, and fraction

4.  Converting decimals to percents (ex 1)

5.  Identifying Percent Amount and Base

6.  Growing by a percentage

Now move on to the energy technology video demonstrations. When you are ready, take the practice quiz to show what you know. If you think you need more practice, ask your instructor if the optional practice assignments would help you.