IM 6.3.6 Lesson: Interpreting Rates

Think of two things you have heard described in terms of “something per something.” Share your ideas with your group, and listen to everyone else’s idea. Make a group list of all unique ideas.

Priya, Han, Lin, and Diego are all on a camping trip with their families. The first morning, Priya and Han make oatmeal for the group. The instructions for a large batch say, “Bring 15 cups of water to a boil, and then add 6 cups of oats.”

• Priya says, “The ratio of the cups of oats to the cups of water is . That’s 0.4 cups of oats per cup of water.”
• Han says, “The ratio of the cups of water to the cups of oats is . That’s 2.5 cups of water per cup of oats.”

Lin decides to cook 5 cups of oats. How many cups of water should she boil?

Diego boils 10 cups of water. How many cups of oats should he add into the water?

Did you use Priya’s rate (0.4 cups of oats per cup of water) or Han’s rate (2.5 cups of water per cup of oats) to help you answer each of the previous two questions? Why?

For each situation, find the unit rates. A cheesecake recipe says, “Mix 12 oz of cream cheese with 15 oz of sugar.”

• How many ounces of cream cheese are there for every ounce of sugar?
• How many ounces of sugar is that for every ounce of cream cheese?

Mai’s family drinks a total of 10 gallons of milk every 6 weeks.

• How many gallons of milk does the family drink per week?
• How many weeks does it take the family to consume 1 gallon of milk?

Tyler paid $16 for 4 raffle tickets.

• What is the price per ticket?
• How many tickets is that per dollar?

If Lin wants to make extra cheesecake filling, how much cream cheese will she need to mix with 35 ounces of sugar?

How many weeks will it take Mai’s family to finish 3 gallons of milk?

How much would all 1,000 raffle tickets cost?

Write a “deal” on tickets for Tyler’s raffle that sounds good, but is actually a little worse than just buying tickets at the normal price.