Proportions Review

Front

What is a unit rate?

Back

A unit rate is a comparison of two different quantities when they are combined together. It expresses how many units of one quantity correspond to one unit of another quantity.

Front

How do you calculate the unit rate from a given distance and time?

Back

To calculate the unit rate, divide the total distance by the total time. For example, if Madeline ran 21.7 miles in 7 hours, the unit rate is 21.7 miles ÷ 7 hours = 3.1 miles per hour.

Front

What is the exchange rate?

Back

An exchange rate is the value of one currency for the purpose of conversion to another. For example, if the exchange rate for Nuevo Sole is 3 to $1, it means 3 Nuevos Soles can be exchanged for 1 dollar.

Front

How do you determine the amount received from exchanging currency?

Back

To determine the amount received, divide the amount of foreign currency by the exchange rate. For example, exchanging 24 Nuevos Soles at an exchange rate of 3 to $1 gives $8.

Front

What is a ratio?

Back

A ratio is a relationship between two numbers indicating how many times the first number contains the second. It can be expressed in various forms, such as fractions, decimals, or with a colon.

Front

How do you simplify a ratio?

Back

To simplify a ratio, divide both terms by their greatest common divisor (GCD). For example, the ratio of 12 dogs to 6 cats simplifies to 2:1.

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal. For example, if a/b = c/d, then a, b, c, and d are in proportion.

Front

How can you solve for an unknown in a proportion?

Back

To solve for an unknown in a proportion, cross-multiply and then divide. For example, if a/b = c/x, then a*x = b*c.

Front

What is the total number of items in a ratio problem?

Back

The total number of items in a ratio problem is the sum of the parts of the ratio. For example, in a ratio of 4 lemon trees to 5 orange trees, the total is 4 + 5 = 9 parts.

Front

How do you find the number of items in a specific category from a total?

Back

To find the number of items in a specific category, multiply the total number of items by the fraction of that category. For example, if there are 120 trees and the ratio of lemon to orange trees is 4:5, then lemon trees = (4/9) * 120 = 53.