Percent Error and Measurement Concepts

Mr. Richards teaches a Grade 7 lesson on percent error, covering various real-world applications. The lesson includes estimating percentages, calculating excess water for plants, determining correct bicycle tire pressure, assessing crowd estimation errors, and measuring tape expansion due to temperature changes. The video concludes with a summary of percent error and its practical uses.

What is the estimated value of 25% of 15.8?

• 3.95

• 4.5

• 5

• 4

If a plant is overwatered by 25%, how much extra water does it receive if it should get 3/4 cup daily?

• 1/2 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?

• 60 psi

• 61 psi

• 63 psi

• 62 psi

How do you calculate the percent error in estimating a crowd size?

• Divide the estimated number by the actual number

• Subtract the estimated number from the actual number and divide by the estimated number

• Subtract the actual number from the estimated number and divide by the actual number

• Add the estimated and actual numbers and divide by two

If a measuring tape expands by 0.00064% per degree above 50°F, how much longer is it at 100°F?

• 0.00096 feet

• 0.96 feet

• 0.096 feet

• 0.0096 feet

What is the percent error if a milk carton is supposed to contain 16 ounces but only has 15 ounces?

• 7.5%

• 5%

• 6.25%

• 10%

If a teacher estimates there are 600 students but there are actually 625, what is the percent error?

• 3%

• 6%

• 5%

• 4%

What is the first step in calculating percent error?

• Subtract the estimated value from the actual value

• Multiply the estimated value by 100

• Find the absolute difference between estimated and actual values

• Divide the estimated value by the actual value

How does temperature affect the length of a metal measuring tape?

• It shortens as temperature increases

• It expands as temperature increases

• It expands as temperature decreases

• It remains the same regardless of temperature

What is the formula to convert a decimal to a percentage?

• Divide by 10

• Multiply by 100

• Divide by 100

• Multiply by 10