Rate review

A rate is a ratio that compares two quantities with different units of measure.

A plane flew $765$765 kilometers in $3$3 hours.

A unit rate of two quantities in a ratio is the number of units of the first quantity for every $\goldD1$start color #e07d10, 1, end color #e07d10 unit of the second quantity.

There are $60$60 minutes in $\goldD1$start color #e07d10, 1, end color #e07d10 hour.

Jen types $42$42 words in $\goldD1$start color #e07d10, 1, end color #e07d10 minute.

Want to learn more about rates? Check out this video.

To find a unit rate, we divide the first quantity in a rate by the second.

A plane flew $765$765 kilometers in $3$3 hours.

The plane flew at a rate of $255$255 kilometers per hour. We can also write the unit rate as $255\text{ km}:\goldD1\text{ hour}$255, start text, space, k, m, end text, colon, start color #e07d10, 1, end color #e07d10, start text, space, h, o, u, r, end text.

Want to learn more about solving unit rates? Check out this video.

Let's look at an example.

Mark can make $\blueE{42}$start color #0c7f99, 42, end color #0c7f99 birthday cakes in $\redE7$start color #bc2612, 7, end color #bc2612 days.

First, we find the unit rate.

Mark makes cakes at a unit rate of $6$6 cakes for every $1$1 day.

Now, we can use the unit rate to find how many cakes Mark makes in $\purpleE5$start color #543b78, 5, end color #543b78 days.