Ratio and Proportional Relationships

Front

What is a ratio?

Back

A ratio is a comparison of two quantities that shows the relative size of one quantity to another, often expressed as 'a to b' or a:b.

Front

What is a unit rate?

Back

A unit rate is a rate in which the second quantity is 1. It shows how much of one quantity corresponds to one unit of another quantity.

Front

How do you calculate the unit cost?

Back

To calculate the unit cost, divide the total cost by the number of units. For example, if Gabby spent $44.10 for 14 gallons of gas, the unit cost is $44.10 ÷ 14 = $3.15 per gallon.

Front

What does a unit rate of 6:1 mean?

Back

A unit rate of 6:1 means that for every 6 units of one quantity, there is 1 unit of another quantity. For example, 30 miles for 5 hours is a unit rate of 6:1.

Front

What is the best buy when comparing prices?

Back

The best buy is determined by finding the lowest cost per unit. For example, if one store sells 36 candies for $7.20, the cost per candy is $7.20 ÷ 36 = $0.20.

Front

What is the formula for finding a unit rate?

Back

The formula for finding a unit rate is: Unit Rate = Total Quantity ÷ Number of Units.

Front

If 20 books cost $10, what is the unit price per book?

Back

The unit price per book is $10 ÷ 20 = $0.50 per book.

Front

What is a proportional relationship?

Back

A proportional relationship is a relationship between two quantities where the ratio of one quantity to the other quantity is constant.

Front

How do you determine if two ratios are equivalent?

Back

Two ratios are equivalent if they simplify to the same fraction or if their cross products are equal.

Front

What is the unit rate of 72 miles in 8 hours?

Back

The unit rate is 72 miles ÷ 8 hours = 9 miles per hour.