Rates, Ratios, and Proportions

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 you have 624 calories in 3 servings, the unit rate is 208 calories per serving.

Front

How do you find the unit rate from a total amount?

Back

To find the unit rate, divide the total amount by the number of units. For example, to find the unit rate of 624 calories in 3 servings, divide 624 by 3, which equals 208 calories per serving.

Front

What is a ratio?

Back

A ratio is a relationship between two quantities, showing how many times one value contains or is contained within the other. For example, the ratio of 5 dogs to 3 cats can be written as 5:3.

Front

How do you write a ratio?

Back

A ratio can be written in three ways: using a colon (5:3), as a fraction (5/3), or with the word 'to' (5 to 3).

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal. For example, if the ratio of dogs to cats is 5:3 and there are 25 dogs, you can set up a proportion to find the number of cats.

Front

How do you solve a proportion?

Back

To solve a proportion, you can cross-multiply and then divide. For example, if you have 5/3 = 25/c, you would cross-multiply to get 5c = 75, then divide by 5 to find c.

Front

What is the ratio of birds to total animals if there are 4 birds and 6 snakes?

Back

The ratio of birds to total animals is 4 to 10, which can be simplified to 2 to 5.

Front

How do you calculate a percentage of a total?

Back

To calculate a percentage of a total, multiply the total by the percentage (as a decimal). For example, to find 60% of 120 students, multiply 120 by 0.60 to get 72 students.

Front

What is the formula for finding the total number of items in a ratio?

Back

To find the total number of items in a ratio, add the parts of the ratio together. For example, in a ratio of 5:3, the total is 5 + 3 = 8.

Front

If 60% of 120 students want to go bowling, how many students is that?

Back

60% of 120 students is 72 students.