Percentage Calculations and Applications

Front

What is a percentage?

Back

A percentage is a way of expressing a number as a fraction of 100. It is often used to compare proportions.

Front

How do you calculate a percentage of a number?

Back

To calculate a percentage of a number, multiply the number by the percentage (in decimal form). For example, to find 20% of 50, calculate 50 * 0.20 = 10.

Front

What does it mean to increase a number by a percentage?

Back

Increasing a number by a percentage means adding that percentage of the number to the original number. For example, increasing 100 by 10% means adding 10 (which is 10% of 100) to get 110.

Front

What does it mean to decrease a number by a percentage?

Back

Decreasing a number by a percentage means subtracting that percentage of the number from the original number. For example, decreasing 100 by 10% means subtracting 10 (which is 10% of 100) to get 90.

Front

If a shirt costs $50 and is on sale for 20% off, what is the sale price?

Back

The sale price is $40. (20% of $50 is $10, so $50 - $10 = $40.)

Front

What is the formula to find the total after a percentage increase?

Back

Total after percentage increase = Original amount + (Original amount * Percentage increase).

Front

What is the formula to find the total after a percentage decrease?

Back

Total after percentage decrease = Original amount - (Original amount * Percentage decrease).

Front

How do you find the percentage of a total?

Back

To find the percentage of a total, divide the part by the whole and then multiply by 100. For example, if 30 out of 150 students passed, the percentage is (30/150) * 100 = 20%.

Front

What is a real-life example of using percentages?

Back

Calculating sales tax, discounts during shopping, or determining grades in school are all real-life examples of using percentages.

Front

If a student scored 75 out of 100 on a test, what is their percentage score?

Back

The percentage score is 75%. (75/100 * 100 = 75%).