1. Percent of Error
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2. Warm Up
Find the percent of change. Tell if it is an increase or decrease. Round to the nearest percent.
1). New: $40 Original: $34
2). New: $76 Original: $150
3). New: $ 340 Original: $ 430
4). New: $20 Original: $ 2
18% increase
49% decrease
21% decrease
900% increase

3. How to Find Percent of Error
Flippable
How to Find Percent of Error
Example Two
Example Three
Example One

4. Percent of Error- Comparing a guess or estimate to an exact value.

5. Example 1: I thought 70 people would come to the concert, but in fact 80 did.
12.5 % error

6. Example 2: The report said the parking lot held 240 cars, but we only counted 200 parking spaces.
20%

7. Example 3: The weather report said we should get 20 mm of rain, but we only got 25 mm.
20%

8. Find the percent of error, round to the nearest whole percent.
Practice.
Find the percent of error, round to the nearest whole percent.
1). Kim thought she would get $50 for her birthday, but she got $75. What is the percent of error?
2). Stephen thought he would run 7 miles Monday morning, but he only ran 5. Find the percent of error.
3). Jan thought she would get 12 questions right on the test, but she only got 8 right. What is the percent of error?
4). Candi predicted her dog would have 6 puppies, but she had 7. Find the percent of error.
33%
40%
50%
14%

9. Explain how to find percent of error.
Closure
Explain how to find percent of error.