### Let’s Think About It

The school is fundraising for a new gym. An amusement park owner has agreed to have a fundraiser at his park. He plans to donate 15% of every dollar spent at the park to the gym fund. How much of every dollar will be donated to the school? Write the amount as a decimal.

In this concept, you will learn how to write percents as decimals.

### Guidance

Percents and decimals are parts of a whole. A percentage is a quantity out of 100. A decimal number with two decimal digits also represents a quantity out of 100.

Compare 34% and 0.34.

34% is 34 out of 100.The decimal 0.34 is 34 hundredths or 34 out of 100. Both quantities represent the same ratio.

A percents can be written as a decimal by replacing “out of 100” with “hundredths.” Remove the percent symbol and move the decimal point two places to the left.

Here is a percent:

Write 45% as a decimal.

First, remove the percent symbol.

Then, move the decimal point two places to the left. Remember that the decimal point is located between the ones and the tenths place.

45% is written as 0.45.

Let’s look at another percent.

Write 5% as a decimal.

First, remove the percent symbol.

Then, move the decimal point in two places to the left. There is no number to the left of 5. Use zero as a place holder.

5% is written as 0 .05

### Guided Practice

Write 15% as a decimal.

First, remove the percent symbol.

Then, move the decimal point two places to the left.

15% is written as 0 .15

### Examples

Write the following percents as a decimal.

#### Example 1

First, remove the percent symbol.

Then, move the decimal point in two places to the left.

17% is written as 0.17.

#### Example 2

First, remove the percent symbol.

Then, move the decimal point in two places to the left.

25% is written as 0.25.

#### Example 3

First, remove the percent symbol.

Then, move the decimal point in two places to the left.

75% is written as 0.75.

### Follow Up

Remember the school fundraiser at the amusement park?

15% of every dollar will be donated towards the school. Convert the percent to a decimal to find how much per dollar will be donated.

Write 15% as a decimal.

First, remove the percent symbol.

Next, move the decimal point two places to the left.

0.15 of every dollar will be donated to the school. Then, multiply $1 by 0.15.

\begin{align*}\$1\times 0.15 = \$ 0.15\end{align*}

$0.15 or 15 cents of every dollar will go to the school.

### Video Review

http://www.youtube.com/watch?v=RvtdJnYFNhc

http://www.mathplayground.com/howto_perfracdec.html

https://www.youtube.com/watch?v=bcK9FpPQfog

### Explore More

Write each percent as a decimal.

- 54%
- 11%
- 6%
- 12%
- 89%
- 83%
- 19%
- 4%
- 9%
- 32%
- 65%
- 88%
- 78%
- 67.5%
- 18.2%