Understanding Percentages and Their Calculations

The video tutorial covers the uses and abuses of percentages, explaining how percentages are essentially fractions per 100. It discusses converting percentages to decimals, using percentages to describe changes, and comparing values. The tutorial also delves into absolute and relative changes, highlighting common mistakes such as shifting reference values and averaging percentages. The importance of understanding vocabulary like 'of' versus 'more than' is emphasized to avoid errors in calculations.

What does the term 'percent' literally mean?

• Per 10

• Per 50

• Per 1000

• Per 100

How do you convert 2.6% into a decimal?

• 26

• 2.6

• 0.26

• 0.026

If 2.6% of 13,000 employees lost their jobs, how many employees is that?

• 26

• 130

• 3380

• 338

What does a 15% decrease in stock value mean?

• The stock value increased by 15%

• The stock value is now 15% of its original value

• The stock value decreased to 15% of its original value

• The stock value decreased by 15% of its original value

What is the absolute change if a house's value drops from $200,000 to $150,000?

• $100,000

• $50,000

• $150,000

• $200,000

How do you calculate relative change?

• Multiply the change by the starting value

• Divide the change by the starting value

• Subtract the old value from the new value

• Divide the new value by the old value

What is the relative change if a stock portfolio increases from $1500 to $2250?

• 100%

• 25%

• 75%

• 50%

What does 'of' imply in percentage calculations?

• Multiplication

• Subtraction

• Division

• Addition

If an item is 25% off, what percentage of the original price is left?

• 25%

• 50%

• 75%

• 100%

What is a common mistake when dealing with percentages?

• Using percentages for comparisons

• Shifting reference values

• Calculating absolute change

• Converting percentages to decimals