Percent Error and Estimation Problems

Mr. Richards teaches a grade seven lesson on percent error, covering estimation of percentages, calculating excess water for plants, determining correct tire pressure, crowd estimation error, and measuring tape expansion due to heat. The lesson includes practical examples and exercises to illustrate the concept of percent error in various contexts.

What is 25% of 15.8 estimated as?

• 4.5

• 5

• 3.95

• 4

If a plant is watered with 3/4 cup daily and receives 25% too much, how much extra water does it get?

• 1/8 cup

• 3/16 cup

• 1/4 cup

• 1/16 cup

A bicycle tire is inflated to 63 psi, which is 5% higher than recommended. What is the correct pressure?

• 61 psi

• 62 psi

• 58 psi

• 60 psi

What is the percent error if a crowd is estimated at 3000 but the actual count is 2486?

• 20.7%

• 15.3%

• 17.5%

• 18.5%

How much longer is a 30-foot tape measure at 100°F if it expands by 0.000064 per degree above 50°F?

• 0.010 feet

• 0.012 feet

• 0.0096 feet

• 0.008 feet

What is the percent error if a measuring tape expands by 0.0096 feet when it should be 30 feet?

• 0.030%

• 0.034%

• 0.032%

• 0.028%

If a milk carton should contain 16 ounces but only has 15, what is the percent error?

• 6.25%

• 5.75%

• 7.25%

• 6.75%

A teacher estimates 600 students in a school, but there are actually 625. What is the percent error?

• 6%

• 4%

• 3%

• 5%

What is the formula to calculate percent error?

• Error divided by actual value

• Error divided by estimated value

• Actual value divided by error

• Estimated value divided by actual value

Which of the following is an example of using percent error?

• Calculating the exact number of items in a box

• Measuring the exact length of a table

• Estimating the number of people in a room

• Predicting the weather for the next day