- Melody Casey
- Mathematics, Social Studies
- Material Type:
- Lesson Plan
- Upper Primary
- Creative Commons Attribution Non-Commercial
Buyer Beware! (AIG IRP)
This activity focuses on the importance of using mathematics to find deals when grocery shopping. Students will analyze data from local grocery store advertisements and determine the best deals by using multiple strategies. This task will also require students to find and compare unit rates, which connects the fourth grade concepts of solving problems involving money and using place value understanding to do arithmetic to the sixth grade standard of determining a unit rate. Once students find which store offers the best deal, they will create a public service announcement teaching others how to find the best deals when grocery shopping. This public service announcement is an opportunity to use precise mathematical language and construct viable arguments. This lesson was developed by NCDPI as part of the Academically and/or Intellectually Gifted Instructional Resources Project. This lesson plan has been vetted at the state level for standards alignment, AIG focus, and content accuracy.
Brief Description of Lesson/Task/Activity: This activity focuses on the importance of using mathematics to find deals when grocery shopping. Students will analyze data from local grocery store advertisements and determine the best deals by using multiple strategies. This task will also require students to find and compare unit rates, which connects the fourth grade concepts of solving problems involving money and using place value understanding to do arithmetic to the sixth grade standard of determining a unit rate. Once students find which store offers the best deal, they will create a public service announcement teaching others how to find the best deals when grocery shopping. This public service announcement is an opportunity to use precise mathematical language and construct viable arguments.
Time Frame: Two-three days
Type of Differentiation for AIGs:
Adaptations for AIGs:
Explanation of How Resource is Appropriate for AIGs: Use place value understanding and properties of operations to perform multi-digit arithmetic. This lesson focuses on current fourth grade standards of using place value and properties of operations to multiply and divide, as well as using the four operations to solve problems involving money. This task also builds essential fourth grade understandings which can lead to concepts such as unit rates. In addition, this task requires students to extend their understanding by dealing with a mathematical situation at a higher, more abstract level.
- Internet access for all students
- Advertisements for a variety of grocery stores
- Sample advertisements printable
Teacher Notes: Although this task does not thoroughly address the Social Studies standard 5.E.2, it is closely related to the concepts that would be taught while teaching it.
1. Make sense of problems and persevere in solving them.
2. Reason abstractly and quantitatively.
3. Construct viable arguments and critique the reasoning of others.
6. Attend to precision.
Stage 1: Engage
Show the following video from Consumer Reports about grocery store marketing tricks.
Say, Yesterday at the grocery store, I was excited to find a great deal on grapes. However, when I got home, I saw this advertisement from a different store (display the provided grape advertisements). Ask students which deal is better. Discuss strategies for solving. Introduce the term “unit price.” In this case, we are trying to find the best price per pound.
Show the provided advertisements for potato chips and dish soap. Determine the best deals and share strategies. As students discuss the dish soap, review the term “unit rate.” Ask students to determine the unit (ounces).
Stage 2: Elaborate
Explain task to students: Families all over the United States are attempting to save money. One way to save is by looking at grocery store advertisements in order to determine which stores have the best deals. Today, your task will be to look at advertisements and websites from grocery stores in our community and determine which store will give consumers the best value. You will need to make direct comparisons between items (e.g., determine the price of water per bottle at one store to the price per bottle at another store). Use mathematical reasoning to justify and explain your solution. Organize and record your findings so you can share them with the group.
After students determine the store with the best value, have class discussion for students to report their findings. Have students share their strategies using strong mathematical reasoning to support their work. Be sure to allow students to critique each other’s thinking. During the conversation, revisit the term unit rate. Ask students to show examples of how they found unit rates during their investigation.
Next, tell students that they will apply their learning from this task to create a public service announcement. Explain: A public service announcement is a print, radio, or television advertisement that raises the public’s awareness of an issue. You must create an announcement that informs about the benefits of shopping for deals and teaches strategies for determining the best deal. Your announcement must use sound mathematical reasoning and precise vocabulary. You may choose to do your public service announcement using any of the following web tools.
- http://www.xtranormal.com (create an animated film)
- http://www.grapheine.com/bombaytv/ (write subtitles for a foreign film)
- http://www.makebeliefscomix.com/ (make a comic strip)
- http://www.voki.com/ (create a talking avatar)
Once all students have created their public service announcements, have the class preview each message. Conduct a group discussion about the clarity of strategies used. Allow students time to ask questions about each other’s reasoning, add on to others thinking, and evaluate whether or not they disagree with the various justifications and solution strategies.
Stage 3: Evaluate
As students determine which grocery store has the best deals, evaluation will be based on the ability to flexibly and correctly select and execute a variety of problem solving strategies. During group discussions, it will be expected that students use precise mathematical vocabulary, thorough explanations, and sound mathematical reasoning. The public service announcement will be evaluated based on the student’s ability to use mathematics to clearly and accurately inform the public of strategies for saving money while grocery shopping.
Teacher Notes: If students need assistance as they are determining the best deals, the teacher can guide them through questioning. For example, Let’s start by just comparing two stores. How can you determine which will allow you to save the most money? How can you keep track of the deals at each store? How much do you predict the price will be per item? What mathematics can we use to find the exact cost of a single item?