Understanding Percent of Change and Error

If a quantity increases from 10 to 13, what is the percent increase?

• 20%

• 30%

• 50%

• 40%

How do you calculate the percent increase?

• Divide the original amount by the increase

• Subtract the increase from the original amount

• Multiply the increase by the original amount

• Divide the increase by the original amount

What is the formula for calculating percent of change?

• Amount of change multiplied by the original amount

• Original amount divided by the amount of change

• Original amount minus the amount of change

• Amount of change divided by the original amount

What is the percent decrease if a radio's price drops from $20 to $15?

• 30%

• 25%

• 20%

• 15%

How do you find the percent decrease?

• Add the decrease to the original amount

• Divide the decrease by the original amount

• Multiply the decrease by the original amount

• Subtract the decrease from the original amount

What is the main difference between percent increase and percent decrease?

• Percent decrease is calculated first

• Percent increase involves a rise in value, while percent decrease involves a fall

• Percent decrease uses a different formula

• Percent increase is always larger

What is percent error used for?

• To find the difference between an estimate and the actual value

• To calculate the exact value

• To determine the original amount

• To increase the accuracy of a measurement

How do you calculate percent error?

• Multiply the error by the actual amount

• Divide the actual amount by the error

• Subtract the error from the actual amount

• Divide the error by the actual amount

If an estimate is $230 and the actual amount is $245, what is the percent error?

• 7%

• 8%

• 5%

• 6%

Why is it important to calculate percent error?

• To ensure estimates are always correct

• To decrease the actual amount

• To understand the accuracy of an estimate

• To increase the original amount