Percent of Change

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Percent of Change

• Lesson 8 7

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Vocabulary

• Percent of Change a ratio that compares the
  change in quantity to the original amount.
• Percent of Increase if the original quantity is
  increased
• Percent of Decrease if the original quantity is
  decreased

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What is Change

• Difference (subtract)
• between
• Original and New

amount of change

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of increase or decrease?
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Proportion for of change
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Need to Know of change

• 1 Identify the original amount. You must
  decide what is the original.
• 2 Amount of Change. How much did the new
  amount increase or decrease by?
• 3 Use the proportion. Solve like a
  proportion. Label where necessary.

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Example

• An 8 ft. tree grows to be 10 ft. tall in the last
  year. What is the trees percent of change?
• Is this change a percent of increase or percent
  of decrease?

n 25
Increase
8
Example 2

• Your salary for the first year was 25,000. In
  the second year, you received a pay cut of 8.
  What is your new salary?
• 2,000 is not my answer. My new salary is
  25,000 n. My salary is

n 2,000
23,000
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Identify as of Increase/ Decrease

• Stock jumps from 3 to 4.5
• Original 21.5 New 20.9
• This years salary 46,825
• Last years salary 45,125
• Two-fifths to three-eighths

of increase!
of decrease!
of increase!
of decrease!
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Find the percent of change!
50

• Stock jumps from 3 to 4.5
• Original 21.5 New 19.35
• This years salary 48,000
• Last years salary 45,000
• Two-fifths to three-eighths

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6.7
6.25
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Ideas to Remember

• Time Reference
• when comparing a calendar year to another, the
  original will usually be the older year.
• 100
• it is possible to have a percent of change
  greater than 100