Percentage Calculations and Concepts

This video tutorial covers how to find a percentage of a number using various methods, including proportional reasoning, multiplication, and cross-canceling. It provides examples such as calculating 28% of 300 and 75% of 20, demonstrating both fraction and decimal approaches. The lesson concludes with a preview of the next topic, finding a percent when the part and whole are known.

What is the relationship between a ratio, a fraction, and a percentage?

• A ratio and a percentage are unrelated.

• A fraction is a type of ratio, and a percentage is a ratio with a denominator of 100.

• A percentage is always smaller than a fraction.

• A ratio is always larger than a percentage.

How do you convert a percentage to a fraction?

• Subtract 10 from the percentage.

• Write the percentage as a fraction with 100 as the denominator.

• Multiply the percentage by 100.

• Divide the percentage by 10.

In the example of 28% of 300 t-shirts, what is the part?

• 84

• 100

• 300

• 28

What is the purpose of using proportional reasoning in percentage calculations?

• To convert percentages to decimals.

• To avoid using fractions.

• To find an equivalent ratio that compares the part to the whole.

• To make the numbers larger.

What is the first step in finding 75% of 20 using proportional reasoning?

• Multiply 75 by 20.

• Divide 75 by 20.

• Write a proportion comparing the part to the whole.

• Write 75% as a decimal.

What is the multiplication factor used to find 75% of 20?

• 4

• 6

• 5

• 3

How do you find the missing part when given a percentage and a whole?

• Subtract the percentage from the whole.

• Divide the whole by the percentage.

• Multiply the percentage by the whole.

• Add the percentage to the whole.

How can cross-canceling simplify multiplication in percentage problems?

• By adding extra steps to the calculation.

• By converting fractions to decimals.

• By reducing the numbers before multiplying.

• By making the numbers larger.

What is the decimal equivalent of 28%?

• 0.028

• 28.0

• 2.8

• 0.28

What is the result of 28% of 300 using decimals?

• 84

• 85

• 83

• 82