MAT 040: Basic Math Learning Unit 10: Handout

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Percent Notation

Meaning of percent

The word percent means hundredths.

The symbol for percent is %.

A percent can be written as a fraction or a decimal.

Convert a percent to a decimal

To convert a percent to a decimal, divide by 100.

A short way to divide by 100 is to move the decimal point two places to the left.

1. Drop the % sign.

2. Move the decimal point two places to the left.

Remember: The decimal point in a whole number is on the right of the number.

Consider the whole number nine. 9 = 9.

To move the point two places to the left, place a zero on the left of nine. You will get .09 if you move the point two places to the left.

Percent to Decimal Examples

Example 1

Convert 5% to a decimal. Drop the percent sign. Move the decimal point two places to the left.

5% = .05

Answer: .05 or 0.05

Example 2

Convert 20% to a decimal. Drop the percent sign. Move the decimal point two places to the left.

20% = .20

Answer: .20 or 0.20 or .2 or 0.2

Example 3

Convert 100% to a decimal. Drop the percent sign. Move the decimal point two places to the left.

100% = 1.00

Answer: 1.00 or 1

MAT 040: Basic Math Learning Unit 10: Handout

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Example 4

Convert 200% to a decimal. Drop the percent sign. Move the decimal point two places to the left.

200% = 2.00

Answer: 2.00 or 2

Example 5

Convert 350% to a decimal. Drop the percent sign. Move the decimal point two places to the left.

350% = 3.50

Answer: 3.50 or 3.5

Example 6

Convert 0.7% to a decimal. Drop the percent sign. Move the decimal point two places to the left.

0.7% = .007

Answer: .007 or 0.007

Example 7

Change to a decimal.

Change the fraction to a decimal.

Drop the % sign.

Move the decimal point two places to the left.

Answer: .005 or 0.005

Example 8

Change to a decimal.

Change the fraction to a decimal.

Drop the % sign.

Move the decimal point two places to the left.

Answer: .0725 or 0.0725

MAT 040: Basic Math Learning Unit 10: Handout

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Example 9

Change to a decimal.

Change the fraction to a decimal.

Drop the percent sign.

Move the decimal point two places to the left.

Answer: or

Example 10

Change to a decimal.

Change the fraction to a decimal.

Drop the percent sign.

Move the decimal point two places to the left.

Answer: or

Convert a decimal to a percent

To convert a decimal to a percent multiply by 100.

A short way to multiply by 100 is to move the decimal point two places to the right.

1. Move the decimal point two places to the right.

2. Attach the % sign.

Decimal to Percent Examples

Example 11

Change 0.56 to a percent. Move the decimal point two places to the right. Attach the percent sign.

0.56 = 56%

Answer: 56%

Example 12

Change 1.4 to a percent. Move the decimal point two places to the right. Attach the percent sign.

1.4 = 1.40 = 140%

Answer: 140%

MAT 040: Basic Math Learning Unit 10: Handout

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Example 13

Convert 3 to a percent. Move the decimal point two places to the right. Attach the percent sign.

3 = 3.00 = 300%

Answer: 300%

Example 14

Convert 0.457 to a percent. Move the decimal point two places to the right. Attach the percent sign.

0.457 = 45.7%

Answer: 45.7%

Convert a percent to a fraction

1. If the number is a whole number, place it over 100.

2. If the number is a fraction, multiply by 1/100.

Percent to Fraction Examples

Example 15

Change 20% to a fraction. Since the number is a whole number, place it over 100. Reduce the fraction if possible.

Answer:

Example 16

Change 3% to a fraction. If the number is a whole number, place it over 100.

Answer:

MAT 040: Basic Math Learning Unit 10: Handout

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Example 17

Change to a fraction. Since the number is a mixed number,

change it to an improper fraction and multiply by 1/100.

The percent symbol % =

Answer:

Example 18

Change to a fraction. Since the number is a fraction,

multiply by 1/100.

The percent symbol % =

Answer:

Example 19

Change 5.2% to a fraction. Place 5.2 over 100 and eliminate the decimal.

Eliminate the decimal in the numerator.

Since there is one decimal place, multiply by

10 in the numerator and denominator.

Reduce the fraction.

Answer:

MAT 040: Basic Math Learning Unit 10: Handout

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Change a fraction to a percent

1. Divide the numerator by the denominator to change the fraction to a decimal.

2. Move the decimal point two places to the right.

3. Attach the % sign.

Fraction to Percent Examples

Example 20

Change to a percent. Change the fraction to a decimal.

Move the decimal point two places to the right.

Attach the % sign.

Answer: 87.5%

Example 21

Change to a percent and write the remainder as a fraction.

Divide to change the fraction to a decimal.

Carry the decimal out two places.

Write the remainder as a fraction.

Move the decimal point two places to the right

Attach the % sign.

Answer:

MAT 040: Basic Math Learning Unit 10: Handout

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Example 22

Change to a percent. First change the fraction to a decimal.

Round the answer to the hundredths place.

It is a repeating decimal.

Move the decimal point two places to the right.

Attach the % sign.

Round the answer to the hundredths place.

Answer:

Example 23

Change to a percent and write the remainder as a fraction.

Divide and change the fraction to a decimal.

Carry the decimal out two places.

Write the remainder as a fraction. 1

Move the decimal point two places to the right.

Attach the % sign.

Answer:

Example 24

Change to a percent. First change the fraction to a decimal.

Round the answer to the hundredths place.

It is a repeating decimal.

Move the decimal point two places to the right.

Attach the % sign.

Round the answer to the hundredths place.

Answer:

MAT 040: Basic Math Learning Unit 10: Handout

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Example 25

Change to a percent and write the remainder as a fraction.

Divide and change the fraction to a decimal.

Carry the decimal out two places.

Write the remainder as a fraction.

Move the decimal point two places to the right.

Attach the % sign.

Answer:

Example 26

Change to a percent. First change the fraction to a decimal.

Round the answer to the hundredths place.

It is a repeating decimal.

Move the decimal point two places to the right.

Attach the % sign.

Round the answer to the hundredths place.

Answer:

Example 27

Change to a percent and write the remainder as a fraction.

Divide and change the fraction to a decimal.

Carry the decimal out two places.

Write the remainder as a fraction.

Move the decimal point two places to the right.

MAT 040: Basic Math Learning Unit 10: Handout

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Answer:

Example 28

Change to a percent and

Round your answer to the hundredths place.

It is a repeating decimal.

Move the decimal point two places to the right.

Attach the % sign.

Answer: Round the answer to the hundredths place.

Percents to Memorize

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