options: 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.

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.)
problem_activity: Task
2 bottles of water cost $5.00.
Fill in the table that shows the costs for 4, 6, and 8 bottles. Find the cost for a single bottle in each case.
| Number of bottles | Cost (\$) | Cost per bottle |
|-------------------|-----------|-----------------|
|       $$2$$       |   $$5$$   |                 |
|       $$4$$       |           |                 |
|       $$6$$       |           |                 |
|       $$8$$       |           |                 |
5 granola bars cost $4.00
Fill in the table that shows the costs for 10, 15, and 20 granola bars. Find the cost for a single granola bar in each case.
| Number of granola bars | Cost (\$) | Cost per bar |
|------------------------|-----------|--------------|
|         $$5$$          |   $$4$$   |              |
|         $$10$$         |           |              |
|         $$15$$         |           |              |
|         $$20$$         |           |              |
Explain why if you can buy $a$ items for $b$ dollars, or buy $2a$ items for $2b$ dollars, the cost per item is the same in either case.


correct_option_index: 2