Understand the concept of a unit rate a/b associated with a ratio a:b with b ≠ 0, and use rate language in the context of a ratio relationship. For example, "This recipe has a ratio of 3 cups of flour to 4 cups of sugar, so there is 3/4 cup of flour for each cup of sugar." "We paid $75 for 15 hamburgers, which is a rate of $5 per hamburger." Expectations for unit rates in this grade are limited to non-complex fractions.
First, students will be introduced to unit rates, by seeing instances of unit rates in the real-world. As examples, miles-per-hour, or cost-per-gallon. Have students think of others. Here's a good video on that. Next, students will learn how ratios and fractions are connected to unit rates. For example, if a recipe has a ratio of 3 cups of flour for every 4 cups of sugar, then there is 3/4 cup of flour for every cup of sugar. If you paid $60 for 5 hamburgers, then you paid $12 for each hamburger. Do not provide problems involving complex fractions. In other words, do not provide problems where fractions appear in the numerator or denominator.
Notes: Why are variables italicized in the Common Core standards preceding this one, but not here?