Rates, Unit Rates, Proportions

Front

What is a rate?

Back

A rate is a ratio that compares two different quantities, often expressed as a fraction. For example, speed is a rate that compares distance to time.

Front

What is a unit rate?

Back

A unit rate is a rate in which the second quantity is one. For example, if you travel 150 miles in 5 hours, the unit rate is 30 miles per hour.

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal. For example, if 5/3 = x/24, then x is the number of ice cream cones sold.

Front

How do you find a unit rate from a total?

Back

To find a unit rate, divide the total quantity by the number of units. For example, if you have 150 miles and 5 gallons, divide 150 by 5 to get 30 miles per gallon.

Front

If 5 ice cream cones are sold for every 3 brownies, how many cones are sold if 24 brownies are sold?

Back

40 ice cream cones are sold.

Front

How do you calculate the cost per item?

Back

To calculate the cost per item, divide the total cost by the number of items. For example, if 5 ice cream bars cost $12.25, then each bar costs $2.45.

Front

What is the formula to find the total cost based on unit price?

Back

Total Cost = Unit Price x Quantity. For example, if hamburger costs $2 per pound and you buy 10 pounds, the total cost is $20.

Front

How do you set up a proportion to solve for an unknown?

Back

Set up a proportion by creating a fraction for each ratio and then cross-multiply to solve for the unknown.

Front

If Toby uses 12 grams of peanuts for 50 cups of peanut butter, how many grams does he use for 75 cups?

Back

Toby uses 18 grams of peanuts for 75 cups of peanut butter.

Front

What is the relationship between rates and proportions?

Back

Rates can be expressed as proportions. For example, if the rate of ice cream cones to brownies is 5:3, this can be written as a proportion.