Difference Between Unit Rate and Rate
Rates and Unit Rates
Ratios are considered rates when they compare two different units, like miles per hour or cost per ounce. A unit rate is one in which the numerator of the fraction is compared to a denominator of one unit. That way you can tell, for instance, like how much just one ounce of something costs.
You’ll see unit rates a lot at the grocery store under or next to the price of an item, it’ll tell you how much that item costs for every one once or for every one thing in the package. Let’s look at a problem dealing with rates and unit rates.
Dave is driving 240 miles to his aunt and uncle’s house. If he gets there in 4 hours how many -and here’s the key right here in the question- how many miles per hour did he drive on average? In that question, they’re telling you how to set up the problem.
They’re telling you to put miles over hours. We’re going to start with that, miles per hour. Now, we can substitute the information in from the problem. They told us how many miles, he’s going 240 miles, and they told us how many hours, 4 hours.
We can put that into our rate 240 miles for his 4 hours. Right now this would be considered a rate since we have two different units our miles and our hours, but to determine our unit rate or to figure out his average we would need to divide or simplify our rate to find or unit rate.
If we want to have a denominator of 1 then we’re going to have to divide 4 by 4 to get our 1. If we divide our denominator by 4 then we must also divide or numerator by 4. 240 divided by 4 is 60. Again, this is miles per hour.
What this unit rate tells us is that on average he was going 60 miles for every 1 hour. Your answer could be written as 60 miles per hour is how fast Dave was going on average.