proportion	An equation that states that two ratios are equal.
rate	A ratio that compares quantities measured in different units. For example, a speed compares the distance traveled to a length of time.
ratio	A comparison of two numbers by division. For example, the ratio of 15 boys in a class to 14 girls in the same class is 15:14.
unit price	A rate in which the quantity is expressed as one unit. If 12 candy bars cost $24, the unit price is $2 per 1 candy bar.
unit rate	A rate in which the second quantity is one unit. If a bird flaps its wings 240 times in 3 minutes, the unit rate of wing flapping is 80 flaps per 1 minute.