1. Percents
Chapter 7
Section 7.5

2. Objective
Students will work with percents and decimals

3. Concept
The word percent means “hundredth” of “divided by 100.” The symbol % is used to represent percent

4. Concept
Going from a decimal to percent, move the decimal 2 spots to the right, add percent sign Going from a percent to a decimal, move the decimal 2 spots to the left, remove percent sign

5. Write the percent as a fraction and decimal 29% 2.6% 637% 0.02% ¼%
Example
Write the percent as a fraction and decimal 29% 2.6% 637% 0.02% ¼%

6. Concept
There are 2 methods that can be used to write a fraction as a percent. 1. divide numbers, move decimal 2. Use the following proportion a / b = x / 100

7. Write each number as a percent 3/5 1/3 4.7
Example
Write each number as a percent 3/5 1/3 4.7

8. Concept
In the next part of this section we will discuss solving percent problems. It is necessary to set up an equation or use a proportion to solve these problems.

9. Concept
In percent problems, the word “of” means “multiply” and the word “is” means “equals” Or you may set up the problem in a proportion then cross multiply to solve is / of = % / 100

10. Example
15% of 180 is what number?

11. Example
23 is 25% of what number?

12. Example
What percent of 64 is 48?

13. Concept
When you solve an equation with decimal coefficients, you can multiply both sides of the equation by a power of 10 (10, 100, and so on) to get an equivalent equation with integral coefficients.

14. Example
Solve 1.2x = x

15. Questions

16. Assignment
Worksheet