Calculating Percentage Increases and Decreases

This tutorial explains how to calculate percentage increases and decreases. It covers two methods for each: finding the percentage of a number and adding or subtracting it, and adjusting the percentage directly. Examples include increasing 20 by 10% and decreasing 70 by 30%. The video also introduces word problems related to these concepts.

What is the original percentage representation of any number?

• 50%

• 75%

• 150%

• 100%

If you increase 20 by 10%, what is the resulting number?

• 20

• 24

• 22

• 18

How do you calculate 10% of 20?

• Multiply 20 by 0.1

• Divide 20 by 10

• Subtract 10 from 20

• Add 10 to 20

What is the first step in the first method of calculating a percentage increase?

• Add the percentage to the number

• Find the percentage of the number

• Multiply the number by the percentage

• Subtract the percentage from 100%

In the second method of percentage increase, what do you do after adjusting the percentage?

• Add to the original number

• Divide by the original number

• Subtract from the original number

• Multiply by the original number

What is the result of decreasing 70 by 30%?

• 60

• 40

• 50

• 49

How do you find 30% of 70?

• Add 30 to 70

• Divide 70 by 3

• Multiply 70 by 0.3

• Subtract 30 from 70

What is the first step in the first method of calculating a percentage decrease?

• Subtract the percentage from 100%

• Add the percentage to 100%

• Multiply the number by the percentage

• Divide the number by the percentage

In the second method of percentage decrease, what do you do after adjusting the percentage?

• Subtract from the original number

• Add to the original number

• Divide by the original number

• Multiply by the original number

What is the final step in both methods of calculating percentage decrease?

• Subtract the result from the original number

• Multiply the result by the original number

• Divide the result by the original number

• Add the result to the original number