options: Understand the concept of a ratio and use ratio language to describe a ratio relationship between two quantities. For example, “The ratio of wings to beaks in the bird house at the zoo was 2:1, because for every 2 wings there was 1 beak.” “For every vote candidate A received, candidate C received nearly three votes.”

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.)

Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations.
problem_activity: A tee-shirt store sells long sleeve (LS) and short sleeve (SS) tee-shirts. In the fall, they stock 4 LS tee-shirts for every 3 SS tee-shirts. In the spring, they stock only 2 LS tee-shirts for every 5 SS tee-shirts.
If the store stocks the same number of tee-shirts in the fall and in the spring, and there are 105 SS tee-shirts in the fall, how many SS tee-shirts does the store stock in the spring?


correct_option_index: 2