More Rate Comparisons
5 min
Narrative
In this Warm-up, students are given two rates—one for a complete pack of a drink and one for an incomplete pack—and asked to decide whether to take the incomplete pack. The work prompts students to consider what makes a good deal and prepares them to make rate comparisons in a shopping context later in the lesson.
Launch
Display the image in the Task Statement (or display an actual four-pack of a beverage with a missing bottle). Read the Task Statement as a class.
Give students a moment of quiet time to think about whether they would take the deal.
Student Task
You enter a store to buy a 4-pack of drinks. You find that the drink is nearly sold out and the last pack on the shelf has only 3 bottles.
A pack of 4 bottles costs $3.16. The clerk offers to sell the incomplete pack for $2.25.
Would you take the deal?
Sample Response
Synthesis
Poll the class for their response and display how many students would and would not take the deal.
Then, ask students: “How could you figure out if the deal is good or not?” Give students a minute of quiet think time to come up with strategies for solving such a problem. Invite a few students to share.
Tell students that in the next activity, they’ll decide whether to take or reject some deals.
Standards
- 6.RP.3.c·Find a percent of a quantity as a rate per 100 (e.g., 30% of a quantity means 30/100 times the quantity); solve problems involving finding the whole, given a part and the percent.
- 6.RP.A.3.c·Find a percent of a quantity as a rate per 100 (e.g., 30% of a quantity means 30/100 times the quantity); solve problems involving finding the whole, given a part and the percent.