1. Chapter 3
Percents
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2. Lesson 3.1 Converting Percents and Finding Values of Percents
Changing a fraction or decimal to a percent
Changing a percent to a fraction or decimal
Changing a percent containing a fraction to a decimal
Finding what percent one number is of another
Finding the given percent of a number
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3. Percents
A percent indicates a value equal to the number of hundredths.
What is a percent?
A percent is another way of showing a fractional relationship. Fractions, decimals, and percents all can be converted from one form to the others.
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4. Changing a Fraction to a Percent
Multiply by 100.
Add the percent sign (%).
For example: 𝟒 𝟓
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5. Changing a Decimal to a Percent
Multiply by 100.
Add the percent sign (%).
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6. Changing a Percent to a Fraction
Drop the percent sign (%).
Write the number as the numerator.
Write 100 as the denominator.
Reduce to lowest terms.
For example:
Convert: 92%
How is a percent written as a fraction?
The number with the percent sign becomes the numerator. The denominator is always 100.
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7. Changing a Percent to a Decimal
Drop the percent sign (%).
Divide by 100 (by moving the decimal point two places to the left).
Express the quotient as a decimal.
For example:
Change: 45%
How is a percent changed to a decimal?
Drop the percent sign, divide by 100, and express the quotient as a decimal. Dividing by 100 can be accomplished by moving the decimal point two places to the left.
Change 45% to a decimal.
Drop the percent sign, then divide by 100, and express the quotient as a decimal: 45 divided by 100 equals Remember to place a zero before the decimal if there are no whole numbers.
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8. Changing a Percent Containing a Fraction to a Decimal (1 of 2)
Drop the percent sign.
Change the mixed number to an improper fraction.
Divide by 100.
Reduce to lowest terms.
Divide the numerator by the denominator, expressing the quotient as a decimal.
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9. Changing a Percent Containing a Fraction to a Decimal (2 of 2)
For example:
Change to a decimal: 𝟏𝟕 𝟏 𝟐 %
Change 17½% to a decimal.
Drop the percent sign; then change the mixed number to an improper fraction. In this example, 17½ is changed to 35/2. Divide the improper fraction by 100 and reduce to lowest terms. Divide the numerator by the denominator. The final answer is
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10. Finding Percentages of Numbers
Write the number after the word of as the denominator.
Write the other number as the numerator.
Divide the numerator by the denominator.
Multiply by 100.
Add the percent sign (%).
For examples:
What percent of 6 is 2?
What percent of 31 is 3 ½ ?
How is the word of used in finding what percent one number is of another?
The number after the word of is used as the denominator of the fraction.
How many places to the right of the decimal point should the decimal fraction be extended?
The decimal fraction should be extended four places to the right of the decimal point.
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11. Finding the Given Percent of a Number
Write the percent as a decimal number.
Multiply by the other number.
For example:
What is 𝟒 𝟓 % of 29?
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