AI Tutor
Imagine one snack stand sells 33 slices of pizza for \12,whileanothersells, while another sells 5slicesforslices for$15.Tofigureoutwhichstandischeaper,youneedtoknowthepriceofjustβˆ—βˆ—. To figure out which stand is cheaper, you need to know the price of just **1$ slice**.
A rate is a comparison of two different quantities with different units, such as dollars and pizza slices.
A unit rate is a special rate that tells you the amount of one quantity for exactly 11 unit of the second quantity.
How do you calculate this single-unit value every time?

Finding the Unit Rate

To find a unit rate, write the ratio as a fraction and divide the numerator by the denominator. The word per means "for every one."
For example, if a car travels 180Β miles180\text{ miles} in 3Β hours3\text{ hours}, divide 180180 by 33 to get 1803=60Β milesΒ perΒ hour\frac{180}{3} = 60\text{ miles per hour}.
What happens if you divide the two numbers in the opposite order?

The Order of Units Matters

The unit you want to count as 11 must always go in the denominator.
Dividing 180Β milesΓ·3Β hours180\text{ miles} \div 3\text{ hours} gives 60Β milesΒ perΒ hour60\text{ miles per hour}, but dividing 3Β hoursΓ·180Β miles3\text{ hours} \div 180\text{ miles} gives 160Β hoursΒ perΒ mile\frac{1}{60}\text{ hours per mile}.