Students learn that converting within and between systems of measurement involves the use of conversion rates, another special type of ratio. To convert units of measurement, they use double number lines, ratio tables, scaling up or down, and unit analysis. Students use models to illustrate the meaning of a unit rate, with each quantity as the denominator. They solve a variety of unit rate problems, determining which unit rates make sense in the context of a problem. Students evaluate prices to determine the better buy and solve problems involving constant speed. Finally, they analyze scenarios and clearly identify the unit rates from tables and graphs.