A **rate** is a *ratio *(comparison) of two different quantities possessing different units of measure. For example, *speed* is a measure of *distance *per unit *time *– distance is measurable and so is time. More specific examples of units are:

**Wage:**$20 per hour**Points per game:**14.5 points per game**Speed:**15 kilometers per hour

Let’s analyze this further. Take the example of wage:

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Anytime your rate is per one unit of whatever, it’s referred to as a **unit rate**. Therefore, $40/2 hours isn’t a unit rate, where as $20/1 hour is.

To convert one rate to another, you have to perform **two simultaneous conversions**. It’s the same process as converting a single unit, except it needs to be performed twice – one conversion each for the numerator and denominator. The videos show several examples of unit rate conversions.

**Part 2** and **part 3** show examples that are slightly more challenging than those above. One of the questions from Part 2 states:

[Convert] 777 gallons per minute to cubic meters per hour

According to the question, you’re expected to go from gallons to meters. A gallon is a unit of *volume* while a meter is a unit of *length*. There’s no clear-path to convert from gallons to meters, so an intermediate step is required.

- Still need more practice, watch Part 3 here. Try to convert each example on your own before watching the solution.