Percentage Calculations and Multipliers

This video tutorial explains how to calculate percentage increases and decreases using two methods: a simple, intuitive technique and a more advanced multiplier method. It covers step-by-step examples for both increasing and decreasing values by a percentage, including contextual examples like calculating discounts. The video also highlights common mistakes and special cases, such as handling percentage changes less than 10% or more than 100%.

What is the first step in calculating a percentage increase?

• Divide the original number by the percentage

• Multiply the original number by 100

• Subtract the percentage from the original number

• Find the percentage of the original number

If you want to increase 120 by 30%, what is the percentage of 120?

• 36

• 150

• 30

• 120

After finding 30% of 120, what is the next step to find the increased value?

• Multiply 36 by 120

• Subtract 36 from 120

• Add 36 to 120

• Divide 120 by 36

What is the first step in calculating a percentage decrease?

• Divide the original number by the percentage

• Multiply the original number by 100

• Find the percentage of the original number

• Add the percentage to the original number

If you want to decrease 80 pounds by 25%, what is the percentage of 80 pounds?

• 60 pounds

• 80 pounds

• 25 pounds

• 20 pounds

After finding 25% of 80 pounds, what is the next step to find the decreased value?

• Multiply 20 pounds by 80 pounds

• Add 20 pounds to 80 pounds

• Divide 80 pounds by 20 pounds

• Subtract 20 pounds from 80 pounds

What is the original price of the headphones before the discount?

• 142 pounds

• 17 pounds 4 pence

• 124 pounds 96

• 12 pounds

How much is the discount worth in the headphones example?

• 24 pounds

• 14 pounds

• 12 pounds

• 17 pounds 4 pence

What is the final price of the headphones after applying the discount?

• 124 pounds 96

• 120 pounds

• 130 pounds

• 142 pounds

In the multiplier method, what is the decimal equivalent of 40%?

• 0.4

• 40

• 4

• 0.04