1. Ch 3 Practice Problems: Percents
Pg 59

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Test review
What number has the greatest value?
0.004, 0.45, 0.8, 0.86
What number has the least value?
1.202, 1.22, 1.2, 1.222
Change the following decimal to a fraction
0.006
2/3 + 4/9 = 3 ½ x 1/8 =
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3. Chapter 3
Percents

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Objectives
Changing a fractions or decimals to a percent and percent to decimals
Finding what percent one number is of another
Finding the given percent of a number
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Percents page 53
A percent indicates a value equal to the number of hundredths.
96% =   96/100
9% = 9/100
77% = 77/100
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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6. Changing a Fraction to a Percent page 53
How can I change 4/5 to a percent?
Multiply by /5 × 100 is 80.
Then add the percent sign to get the final answer, 80%.
What is the equivalent percentage of 4/5?
To determine the equivalent percentage, multiply by 100. In this case, 4/5 × 100 is 80. Then add the percent sign to get the final answer, 80%.
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7. Changing a Decimal to a Percent Page 54
Multiply by the decimal number by 100.
Or move your decimal two places to the right.
Add the percent sign (%).
Express as a percent
0.421 x 100 = 42.1%
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8. Changing a Percent to a Fraction page 54
How is a percent written as a fraction?
Drop the % sign.
Write the remaining number as the numerator.
The denominator is always 100.
45% =
45/100 then reduce to lowest terms
9/20
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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9. Changing a Percent to a Fraction page 54
Example: 92% Drop the percent sign. Write the number as the numerator with 100 as the denominator. 92/100 Reduce to lowest terms, which is 23/25.
What fraction is equal to 92%?
Drop the percent sign. Write the number as the numerator with 100 as the denominator, which in this example is 92/100. Reduce to lowest terms, which is 23/25.
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10. Changing a Percent to a Decimal page 55
How is a percent changed to a decimal?
Drop the % sign.
Divide the remaining number by 100.
Dividing by 100 can be done by moving the decimal point two places to the left or you can use your calculator.
Express the quotient as a decimal.
32% = 0.32
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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11. Changing a Percent Containing a Fraction to a Decimal page 55
How is a percent containing a fraction changed to a decimal?
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
How is a percent containing a fraction changed to a decimal?
First change the mixed number to an improper fraction. Multiply the denominator of the fraction by the whole number, then add the product to the numerator of the fraction. The sum is then placed over the denominator.
What is the denominator of all whole numbers?
The denominator of all whole numbers is 1.
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12. Changing a Percent Containing a Fraction to a Decimal page 55
Example: 17 % 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
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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Bell Work 1/22
Change the following to a proper fraction reduced to lowest terms.
3/4%
24.8%
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15. Finding Percentages of Numbers
What percent of 24 is 9?
Remember this equation is/of = x%/100
9/24 = x%/100
X= 37.5%
Write the number after the word of as the denominator.
Write the other number as the numerator.
Divide the numerator by the denominator
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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16. Finding Percentages of Numbers
Example 2: What percent of 6 is 2? 2/6 = x%/100 X= 33.3%
What percent of 6 is 2?
Write the number after the word of as the denominator and the other number as the numerator (in this example, 2/6). Divide the numerator by the denominator (0.3333). Multiply the decimal fraction by 100 and add the percent sign to get the answer (33.33%).
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17. Finding Percentages of Numbers (cont’d)
Example 3:
What percent of 31 is 3 ?
3 ½ /31 = x%/100
X= 11.29%
Divide the numerator by the denominator gives 3.5/31 (0.1129).
Multiply the decimal fraction by 100 and add the percent sign to get the answer (11.29%).
What percent of 31 is 3 1/2?
In this example, dividing the numerator by the denominator gives 3.5/31 (0.1129). Multiply the decimal fraction by 100 and add the percent sign to get the answer (11.29%).
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18. Finding the Given Percent of a Number
Write the percent as a decimal number.
Multiply by the other number.
Example: What is % of 29?
The decimal number would be Then multiply by the other number: × 29 =
What is 4/5% of 29?
Write the percent as a decimal number. In this example, the decimal number would be Then multiply by the other number: × 29 =
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