Unit rate

A unit rate is a rate expressed as so much per 1 unit of the second quantity: 60 km per 1 hour, $3 per 1 kg, 12 words per 1 minute.

To find it, divide both parts of the rate by the second quantity. On a double-number-line, it is the value under the top line's 1. Because it fixes the second quantity at one, a unit rate makes different rates easy to compare.