Percent Change and Percent Error Explained

Miss Lobato explains the concepts of percent change, including percent increase, percent decrease, and percent error. She provides examples for each concept, demonstrating how to calculate the percent change in various scenarios, such as changes in gas prices and DVD recorder prices. The video also covers how to determine percent error using a jar of marbles as an example. The tutorial aims to prepare students for their tests by reviewing these mathematical concepts.

What are the two types of percent of change?

• Percent of increase and percent of error

• Percent of increase and percent of decrease

• Percent of decrease and percent of error

• Percent of change and percent of error

In the percent of increase example, what was the original gas price in 1980?

• $1.30

• $2.30

• $2.95

• $1.65

How do you convert a decimal to a percent?

• Divide by 100

• Subtract 100

• Multiply by 100

• Add 100

In the percent of decrease example, what was the new price of the DVD recorder?

• $280

• $220

• $60

• $200

What is the formula to calculate the percent of decrease?

• Amount of increase divided by the original amount

• Amount of decrease divided by the original amount

• Amount of error divided by the actual amount

• Original amount divided by the amount of decrease

What is the percent error if you guessed 300 marbles but there were actually 400 marbles?

• 35%

• 30%

• 25%

• 20%

How do you find the amount of error in percent error calculation?

• Divide the guess by the actual amount

• Subtract the guess from the actual amount

• Multiply the guess by the actual amount

• Add the guess to the actual amount

In the additional example, how many yards of fabric were needed originally?

• 12 yards

• 15 yards

• 20 yards

• 18 yards

What is the percent of change if the fabric increased from 15 yards to 18 yards?

• 20%

• 25%

• 18%

• 15%

What should you do if you need further clarification on the concepts?

• Guess the answers

• Ask the teacher for help

• Skip the test

• Ignore the problem