standard_description: 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: Problem 1
At the store, you see oranges on sale at 1 pound for $3. At a different store, your brother sees oranges on sale at 3 pounds for $8.
Do the oranges cost the same at both stores? Which store offers the better deal? Justify your answer.
Problem 2
Callie biked 12 miles in 3 hours. Carter biked 10 miles in 2 hours.
Represent each person's trip with a double number line. Explain how you can see that they are not going the same speed.
Problem 3
Density is the relationship between the mass of an object and its volume, or amount of space it takes up. A scientist finds a rock and determines its mass to be 18 grams and its volume to be 4 cm
$$^{3}$$
. Another rock is found with a mass of 63 grams and a volume of 14 cm
$$^{3}$$
.
Draw two double number lines to compare the two rocks. Do the rocks have equivalent ratios of mass and volume? Do they have the same density?


aligns: no