Percentage Calculations and Concepts

This tutorial explains how to calculate percentage increases and decreases. It demonstrates 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%.

What is the original percentage representation of any number?

• 150%

• 100%

• 75%

• 50%

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

• 18

• 22

• 24

• 20

How do you calculate 10% of 20?

• Multiply 20 by 0.1

• Divide 20 by 10

• Add 10 to 20

• Subtract 10 from 20

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

• Subtract the percentage from 100%

• Divide the number by the percentage

• Add the percentage to 100%

• Multiply the number by the percentage

In the second method of percentage increase, what is the new percentage used for calculation?

• 90%

• 120%

• 110%

• 100%

What is the result of decreasing 70 by 30%?

• 49

• 60

• 40

• 50

How do you find 30% of 70?

• Add 30 to 70

• Subtract 30 from 70

• Divide 70 by 3

• Multiply 70 by 0.3

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

• Add the percentage to 100%

• Multiply the number by the percentage

• Subtract the percentage from 100%

• Divide the number by the percentage

In the second method of percentage decrease, what is the new percentage used for calculation?

• 80%

• 70%

• 60%

• 90%

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

• Multiply the result by the original number

• Divide the result by the original number

• Subtract the result from the original number

• Add the result to the original number