National Agricultural Literacy Curriculum Matrix
Search Lesson Plans & Companion Resources
That Was Then, This Is Now
Grade Level(s)
3  5
Estimated Time
Two 40minute sessions and 1 homework assignment
Purpose
Students will learn about food prices and how they have changed over time as they perform mathematical computations, analyze data charts, and compare and contrast statistical information.
Materials
 Reading Chart I and II activity sheets
 Average Prices of Food—Retail chart
 The Price of Food Today homework assignment
 Colored Pencils
 Graph paper
Essential Files (maps, charts, pictures, or documents)
 Reading a ChartI Activity Sheet
 Reading a ChartII Activity Sheet
 Reading a ChartI Answer Key
 Reading a ChartII Answer Key
 Average Prices of FoodRetail Chart
 The Price of Food Today Homework Assignment
Vocabulary
farmer: someone who grows animals or crops for food and fiber
commodity: a primary agricultural product that can be bought and sold
retail food prices: the cost of food at a grocery store or other retail outlet
Did you know? (Ag Facts)
 U.S. consumers spend just 10 percent of their disposable income on food each year.^{1}
 For every retail dollar spent on food, an average of 17 cents goes to farmers and ranchers.^{1}
 For every retail dollar spent on food, an average of 83 cents goes to offfarm costs (processing, distribution, retail, etc.).^{1}
Background Agricultural Connections
This lesson includes information on how food price data can be used to make mathematical computation practice interesting and informative. Review the materials and revise them to meet the needs of your students.
You may choose to customize the lesson to include current and past newspaper grocery ads. Consider comparing commodity prices from one season to the next and from one year to another. Statistics and colorful graphs are available from a variety of sources.
As you use this lesson, it is important for students to realize that the United States has the safest, most abundant food supply in the world. Most farmers do not make a lot of money producing the food Americans consume. In fact, people who farm most often do it because they have a passion for it. Today, over 90% of farm families have some income that comes from outside of farming.^{2} Profit made in agriculture is most often accrued on the marketing end. It may be interesting for your students to meet a producer and learn about his/her operation.
Interest Approach – Engagement
 Choose a food item and write the steps from farm production to consumption on the board from left to right. For example:
 Milk is produced by cows on a dairy farm; a truck picks the milk up and takes it to a processing plant; the milk is processed and packaged into butter, yogurt, and other dairy products; finally the product is transported to grocery stores where it is purchased and consumed.
 Eggs are produced by chickens on a farm. Next, the eggs are cleaned, packaged and checked for quality at a processing plant. Finally, the eggs are transported to grocery stores where they are sold to consumers.
 As students visualize the different steps of the production of their food, help them understand that the food is sold on each level. When they buy food at the grocery store they are paying the farmer to produce it, the processor to prepare it for consumption, and the grocery store for putting it on their shelves.
 Ask the students, "What costs are associated with purchasing food at the grocery store?"
Procedures
 Review the Reading Chart activity sheets. If necessary, rewrite the activity sheets or create math problems that supplement them.
 Introduce your students to the lesson by having them think about the prices their family pays for specific food items and how they think that price is determined. Possible discussion and/or writing prompts are listed below.
 If you were to ask your parents if the price of food is going up or down what would they say?
 On average, is it less expensive, more expensive, or about the same to eat at a restaurant than at home? Explain.
 How do you think the price of food is determined?
 Do the farmers who grow the crops make a lot of money on the food you are eating?
 If you were to compare the price of food in the United States to the price of food in other countries, would it be more or less expensive?
 Introduce your students to the Average Prices of Foods—Retail chart. In general, discuss what the chart shows. Review the meaning of average.
 Have the students complete the student activity sheets and the homework assignment. Part of the homework assignment requires students to make a graph. Be sure they have the rough drafts of their graphs approved before preparing their final copies.
 Share the graphs the students have created. Display the student graphs in the library, hallways, grocery stores, and at special events such as parent meetings and open houses.
Concept Elaboration and Evaluation
After conducting these activities, review and summarize the following key concepts:
 The cost of buying food pays for the production of the food on the farm, the processing or packing of the food, as well as the work of the grocer who sells it.
 The cost of food changes as years pass and also from season to season.
We welcome your feedback! Please take a minute to tell us how to make this lesson better or to give us a few gold stars!
Enriching Activities

Convert the homework activity to a class field trip. Have students work in teams of two as they find information at the grocery store.

Create large colorful graphs of the information they collected at the grocery store. Display the student graphs at the stores the students visited.

Use grocery ads to determine the prices of the food items in the homework assignment.

Use the Food and Farm Facts Booklet available from the American Farm Bureau Federation to illustrate a variety of graphic ideas as well as information on the current status of American agriculture.
Suggested Companion Resources
 Tuttle's Red Barn: The Story of America's Oldest Family Farm (Book)
 Food and Farm Facts Booklet (Booklets & Readers)
Sources/Credits
Author(s)
California Foundation for Agriculture in the Classroom, Pamela Emery
Organization Affiliation
California Foundation for Agriculture in the Classroom
Agricultural Literacy Outcomes
Food, Health, and Lifestyle
 Explain the costs associated with producing and purchasing food. (T3.35.d)
Education Content Standards
Within ECONOMICS
Economics Standard 2: Decision Making

Objective
ObjectiveMake effective decisions as consumers, producers, savers, investors, and citizens.
Economics Standard 7: Markets and Prices

Objective
ObjectiveIdentify markets in which they have participated as a buyer and as a seller and describe how the interaction of all buyers and sellers influences prices. Also, predict how prices change when there is either a shortage or surplus of the product available.
Common Core Connections
Mathematics: Practice Standards

CCSS.MATH.PRACTICE.MP1
CCSS.MATH.PRACTICE.MP1Make sense of problems and persevere in solving them. Students start by explaining to themselves the meaning of a problem and looking for entry points to its solution. They analyze givens, constraints, relationships, and goals. They make conjectures about the form and meaning of the solution and plan a solution pathway rather than simply jumping into a solution attempt. They consider analogous problems, and try special cases and simpler forms of the original problem in order to gain insight into its solution. They monitor and evaluate their progress and change course if necessary. Students check their answers to problems using a different method, and they continually ask themselves, “Does this make sense?” They can understand the approaches of others to solving complex problems and identify correspondences between different approaches.

CCSS.MATH.PRACTICE.MP2
CCSS.MATH.PRACTICE.MP2Reason abstractly and quantitatively. Students make sense of quantities and their relationships in problem situations. They bring two complementary abilities to bear on problems involving quantitative relationships: the ability to decontextualize—to abstract a given situation and represent it symbolically and manipulate the representing symbols as if they have a life of their own, without necessarily attending to their referents—and the ability to contextualize, to pause as needed during the manipulation process in order to probe into the referents for the symbols involved. Quantitative reasoning entails habits of creating a coherent representation of the problem at hand; considering the units involved; attending to the meaning of quantities, not just how to compute them; and knowing and flexibly using different properties of operations and objects.

CCSS.MATH.PRACTICE.MP5
CCSS.MATH.PRACTICE.MP5Use appropriate tools strategically. Students consider the available tools when solving a mathematical problem. These tools might include pencil and paper, concrete models, a ruler, a protractor, a calculator, a spreadsheet, a computer algebra system, a statistical package, or dynamic geometry software. Students at various grade levels are able to identify relevant external mathematical resources, such as digital content located on a website, and use them to pose or solve problems. They are able to use technological tools to explore and deepen their understandings of concepts.

CCSS.MATH.PRACTICE.MP6
CCSS.MATH.PRACTICE.MP6Attend to precision. Students try to communicate precisely to others. They try to use clear definitions in discussion with others and in their own reasoning. They state the meaning of the symbols they choose, including using the equal sign consistently and appropriately. They are careful about specifying units of measure, and labeling axes to clarify the correspondence with quantities in a problem. They calculate accurately and efficiently, express numerical answers with a degree of precision appropriate for the problem context.