Finding Percent of a Number with Proportions

The video tutorial explains how to find the percentage of a number using proportions and ratios. It covers several examples, including calculating 15% of 20, 25% of 90, and 5% of 12. The tutorial also demonstrates a real-life application of percentages in calculating discounts on a shirt. The instructor uses cross multiplication and reasoning to solve these problems, emphasizing the importance of understanding the relationship between parts and wholes in percentage calculations.

What does a percentage represent in terms of a ratio?

• A part out of fifty

• A part out of a thousand

• A part out of ten

• A part out of a hundred

How do you set up a proportion for finding percentages?

• Assuming all values are equal

• Using only known values

• Using variables for unknowns

• Ignoring the percentage value

What is 15% of 20?

• 3

• 4

• 2.5

• 5

How can cross multiplication be used in percentage calculations?

• To subtract values

• To add percentages

• To find equivalent ratios

• To divide percentages

What is 25% of 90?

• 25

• 22.5

• 23

• 20

Can percentages result in decimal values?

• Yes, always

• No, never

• Yes, sometimes

• Only in specific cases

What is 5% of 12?

• 1

• 0.5

• 1.2

• 0.6

Why might lower percentages result in smaller numerical outcomes?

• None of the above

• Due to the nature of percentages

• Due to lower base values

• Due to higher base values

What is the discount amount when 20% off is applied to a $24 shirt?

• $5.00

• $4.00

• $4.80

• $3.80

How do you verify if your percentage calculation makes sense?

• Check if the result is a whole number

• Compare with the original amount

• Ask a friend

• Guess and check