A rate is a special ratio that compares two quantities measured in different units. It is a comparison of two different quantities. For example, miles per hour, price per pound, or words per minute are all examples of rates.
To calculate a rate, you need to divide one quantity by the other. The formula for calculating rate is:
Rate = Quantity 1 / Quantity 2
When expressing a rate, it is important to include the units. For example, if the rate is 60 miles per hour, both "miles" and "hours" should be included to indicate the units being compared.
A unit rate is a rate with a denominator of 1. It is often used to compare the prices of items. For example, if a 2-pound bag of rice costs $4, the unit rate is $2 per pound.
Rates can be used in proportions to solve problems. For example, if 3 gallons of juice cost $6, you can set up the proportion 3 gallons / $6 = x gallons / $12 to find the cost of 6 gallons.
Rates are used in many real-life situations, such as speed (miles per hour), unit pricing in stores, and performance measures like words per minute in typing or reading speed.