Unit Rates and Percentages

Front

What is a unit rate?

Back

A unit rate is a comparison of two different quantities where one of the quantities is expressed as a quantity of one. For example, if apples cost $1.50 per pound, the unit rate is $1.50 per 1 pound.

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 30% of 80, calculate 80 x 0.30 = 24.

Front

What is the formula to find the percent of a part compared to a whole?

Back

The formula is: (Part/Whole) x 100 = Percent. For example, if there are 6 blue jellybeans out of 30, the percent is (6/30) x 100 = 20%.

Front

If an item costs $1.50 per pound, how much would 3 pounds cost?

Back

To find the cost, multiply the price per pound by the number of pounds: $1.50 x 3 = $4.50.

Front

What does 100% of a number represent?

Back

100% of a number is equal to the number itself. For example, 100% of 50 is 50.

Front

How do you convert a fraction to a percentage?

Back

To convert a fraction to a percentage, divide the top number (numerator) by the bottom number (denominator) and then multiply by 100. For example, 1/4 = (1 ÷ 4) x 100 = 25%.

Front

What is the relationship between unit rates and ratios?

Back

Unit rates are a specific type of ratio that compares a quantity to one unit of another quantity. For example, if a car travels 300 miles in 5 hours, the unit rate is 60 miles per hour.

Front

How do you find the total cost of multiple items at a unit price?

Back

Multiply the unit price by the quantity of items. For example, if apples cost $1.50 each and you buy 4, the total cost is $1.50 x 4 = $6.00.

Front

What is a real-world example of using percentages?

Back

Sales tax is a common example. If a shirt costs $20 and the sales tax is 5%, the total cost is $20 + (20 x 0.05) = $21.

Front

How do you find the percent increase or decrease?

Back

To find percent increase: (New Value - Original Value) / Original Value x 100. For decrease, use: (Original Value - New Value) / Original Value x 100.