Percents (Lesson 1) Review

Percents (Lesson 1) Review

Algebra 1

Mrs. LaGrange

Percent

The word percent means "per hundred" or "hundredths."

Percents Expressed

Percents can be expressed as:
1.  A ratio in words.

2.  A fraction.  

3.  A decimal.

4.  A percent.

Changing a Ratio in Words to a Percent

To change a ratio in words to a percent follow the following steps:

1. Given the Ratio

2. Rewrite the ratio as a fraction.

3. Divide the numerator by the denominator.

4. Multiply by 100

5. Write your percent.

Changing a Ratio in Words to a Percent (when the denominator is not equal to 100.)

When the denominator does not equal 100 we follow the same steps to change a ratio in words to a percent.

Follow these steps:

1. Given the Ratio

2. Rewrite the ratio as a fraction.

3. Divide the numerator by the denominator.

4. Multiply by 100

5. Write your percent.

Fill in the Blanks

Write the following ratio in words as a percent.

70 out of 100

Fill in the Blanks

Write the following ratio in words as a percent.

7 out of 10

Fill in the Blanks

Write the following ratio in words as a percent.

20 out of 25

Rewriting a fraction as a percent.

To rewrite a fraction as a percent:

1. Write the fraction.

2. Divide the numerator by the denominator

3. Multiply your answer by 100.

4. Rewrite your percent.

Fill in the Blanks

Change the fraction to a percent.

 $\frac{98}{100}$  

Fill in the Blanks

Change the following fraction to a percent.

 $\frac{6}{10}$  

Fill in the Blanks

Change the following fraction to a percent.

 $\frac{15}{20}$  

Change a percent to a fraction.

We can go in reverse and change a percent to a fraction.

1. Write the number over 100.

2. Simplify the fraction.

Fill in the Blanks

Write the following percent as a fraction.

97%

Fill in the Blanks

Write the following percent as a fraction. (Reduce to lowest terms.)

75%

Change decimals to percents

Recall: Hundredths = Percent

Decimals can easily be changed to a percent simply by multiplying by 100.

(Move the decimal to the right 2 places.)

Fill in the Blanks

Rewrite the decimal as a percent.

.85

Fill in the Blanks

Rewrite the decimal as a percent.

.7

Fill in the Blanks

Rewrite the decimal as a percent.

.07

Change a percent to a decimal

To change a percent to a decimal simply divide by 100. (Move the decimal place 2 places to the left.)

Fill in the Blanks

Rewrite the percent as a decimal.

70%

Fill in the Blanks

Rewrite the percent as a decimal.

75%

Fill in the Blanks

Write the following percent as a decimal.

7%

Great Job!

Today we have seen how to:

• Change a ratio in words to a percent

• Change a fraction to a percent

• Change a percent to a fraction

• Change a decimal to a percent

• Change a percent to a decimal