Hands-on Activity Cookie Mining:
Ore Production & Cost-Benefit Analysis

Learning Objectives

After this activity, students should be able to:

• Explain what is meant by the “cost of production.”
• Complete a profit and loss statement.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

Common Core State Standards - Math

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each student needs:

• 1 sheet graph paper
• 1 chocolate chip cookie
• pencil
• at least 2 mining tools; choose from paperclip, round toothpick, flat toothpick
• Cookie Mining Worksheet

To share with the entire class:

• paperclips
• round toothpicks
• flat toothpicks
• Cookie Mining Reference Sheet, either write its information on the classroom board or make copies as a handout
• clock or watch, for timing students’ mining work
• (optional) calculators

Worksheets and Attachments

Pre-Req Knowledge

A familiarity with renewable and nonrenewable resources and basic math skills (addition and subtraction).

Introduction/Motivation

Wouldn’t it be nice if everything we made did not cost us a single penny? Unfortunately, this is not the case. When engineers are designing products, they need raw materials. Materials cost money, labor costs money, and many other variables that go into production projects cost money. In the real world, engineers must design their products with many other considerations in mind as well—ethical, environmental, professional, societal, the list goes on! However, today we will keep the focus on cost. Remember, engineers almost always need to design within a budget and make sure the overall project makes a profit.

One type of nonrenewable energy source is ore, such as coal. Today you will work as engineers who are mining for ore who must keep in mind the cost of production.

Procedure

Background

The cost of production is key when obtaining nonrenewable and renewable raw resources. Engineers focus on both the science and economics behind acquiring natural resources. Engineers do cost-benefit analyses to make responsible decisions about how to obtain the resources. They look to maximize profits while also considering how the environment— the nearby air, land and water—might be impacted through mining by (hopefully) choosing the least destructive mining method. For example, surface mining and underground mining have very difference costs and ways that they impact the lithosphere.

Before the Activity

• Make copies of the Cookie Mining Worksheet, which is a simple profit and loss statement template.
• Write the Cookie Mining Reference Sheet information (also below) on the classroom board OR make copies as a handout.

Cookie Mining Reference Information

Startup costs: Before mining timing starts:

Land Cost

1 cookie = $1,200

Land area = squares on graph paper (partial squares = 1 full square)

Tools Cost (choose at least 2)

1 paperclip = $500

1 round toothpick = $300

1 flat toothpick = $100

After mining timing ends:

Revenue from Sale of Chocolate Ore

Chips that fall off of the graph paper = “lost”

Whole, clean chip = $500 each

“Dirty” chip = chips that have cookie remains on them = $200 each

Partial chip (must be combined to form amount of ore in one chip) = $100 each

Labor Cost (Time)

Ongoing mining operation = $50 per minute

Land Reclamation Cost

Original land (cookie) = $30 per square

Additional land (circles) made during reclamation = $50 per square

With the Students

1. Ask the class the pre-activity questions, as described in the Assessment section.
2. Present to the class the Introduction/Motivation content to kick-off the activity.
3. Give each student a piece of graph paper and one chocolate chip cookie.

4. With the class, go through the cookie mining reference information. Have students decide on their tools, realizing that tools are one cost of production that will figure into their final profits.
5. Before timing starts, have students trace their cookies on the graph paper and count the squares inside.
6. Place the cookie back inside the circle. Explain that from this point on the cookie may not be touched with their hands. Direct students to start mining while noticing the clock in order to keep track of how much time the entire class spends at cookie mining (labor cost tracked by minutes).
7. Have students dig out as many chocolate chips as they can using only their tools.
8. After students have mined their cookies, they begin reclamation by using only their tools.
9. Once as many of the remaining cookie pieces are placed back inside the circle, have students draw additional circles around the crumbs that are not placed inside the main cookie circle.
10. Tell the students: When all mining and reclamation is complete and you are ready to sell your chocolate ore, arrange them in such a way that they may be easily counted, and raise your hand. For each student, note the amount of minutes they spent cookie mining.
11. Profit-loss statement: Have students fill out the worksheet, which guides them through tabulating the costs of land (cookie), mining equipment, labor/time, mining operations, and land reclamation, as well as calculating the mining revenue and profit (net revenue).
12. Cost-benefit analysis: Discuss with students the differences in costs among their peers along with how their cookies are examples of different kinds of mining. For example surface mining in which students destroy the cookie in the process vs. underground mining in which the cookie (land) remains largely intact.
13. Conclude through a class discussion, asking students the post-activity questions, as provided in the Assessment section.

Vocabulary/Definitions

cost-benefit analysis: A systematic approach for calculating and comparing benefits and costs of a project. Abbreviated as CBA.

expense: The cost to pay for something, such as material goods, services, equipment or labor.

lithosphere: The crust and upper mantle of the Earth.

ore: A type of rock that contains sufficient minerals of a desirable element that can be extracted from the rock. Ores are extracted from the Earth through mining, and then refined to obtain valuable elements.

reclamation: To restore what once was, such as to restore land that has been mined to a natural or usable state.

revenue: The amount of money (or income) that a business makes from the sale of goods and services before expenses and cost of production are subtracted.

surface mining: The mass removal of the soil and rock surface of an area of land to some depth in order to extract ore, minerals and/or resources. Sometimes called strip mining.

underground mining: Sub-surface extraction of ore, minerals and/or resources from below the Earth’s surface with minimal damage to the overlying rock and soil.

Assessment

Pre-Activity Assessment

Before Mining: Ask the class:

• What are some costs of production that we need to consider when mining? (Possible student responses: Costs of tools, equipment, labor, trucking; electricity to power the mine, tools and equipment; any environment and ecosystem destruction or harm such as the loss of trees, plants, wildlife, and polluted soil, water and air.)
• What kind of resource is mineral ore? (Answer: A nonrenewable resource.)

Activity Embedded Assessment

During Mining: Ask the class:

• In our mining simulation (cookies), what can you do to make the end cost less in order to generate higher profit? (Possible student responses: Be careful while removing chips, work quickly.)

Post-Activity Assessment

After Mining: Ask students the following post-activity questions:

• Was the chocolate ore/minerals evenly distributed throughout the cookie mines? (Expect students to say no.)
• Were you able to restore the land? (Expect students to say that it was very difficult to impossible.)
• How did knowing in advance that the land must be restored affect the time you took for mining? (Expect students to say that knowing this increased the mining time [and cost] because of the extra care taken to minimize land [cookie] destruction during mining and the time taken to restore the land after mining.)
• What do we mean by the “cost of production”? What does that include? (Answer: The cost of production is the sum of all the costs of all the resources that went into making something. In this case, the cost of production included expenses for land, tools, labor, and land reclamation.)
• Explain why legislation that requires land to be restored after mining makes mining more expensive. (Answer: Land reclamation is another expense to include in the cost of production.)
• What is the “bottom line” of your profit and loss statement (worksheet)? Did you make a profit? (Answer: The “bottom line” is the profit from the entire project. It is what is left when you subtract your cost of production from your revenue. If it is negative, it is a loss!)
• What is the conclusion of your cost-benefit analysis? Were your costs more or less than the benefits/gains?
• From what you have learned, how would you refine your mining decisions and approach to increase your profit? What is your advice to other cookie miners? (Possible answers: Choose certain tools and no more than necessary. Be quick since time adds up to more labor costs, but be careful and skillful in mining to limit land destruction [to reduce reclamation costs] and because intact and clean, big chips sell for more. Or dream up new approaches that work better such as wetting the cookie to soften it up before ore extraction?!)
• What additional costs and goals might need to be taken into consideration in real-world mining engineering? (Answer: The amount of destruction and pollution to the lithosphere when deciding the method to obtain ore, the variabilities of ore concentration within the land and the geological makeup of the land where the ore is located. Additional costs such as trucking, electricity and fuel.)

Activity Extensions

The Surface Mining Control and Reclamation Act of 1977 is the primary law that regulates the environmental effects of coal mining in the U.S. Extend this activity with the following assignment:

• Outline the Surface Mining Control and Reclamation Act.
• Identify when and discuss why the act was written.
• Speculate about the people and organizations who are most likely to support and oppose the act. (Answer: Supporters might be local citizens who do not want any destruction to the environment. Opponents might be mining operators who do not want any expenses added to the cost of production.)
• Compose a list of minerals used in and around your home, and how they are used. (Possible answers: Aluminum, asbestos, borax [for cleaning], chrome, clay, copper, diamond [jewelry], garnet, gold, granite, graphite, gypsum, iron [pots and pans], marble, nickel, perlite [in potting soil], phosphate, potassium, pumice, quartz, silica sand [made into glass], silver, slate, sulfur, talc [in baby powder], vermiculite, zinc; many for plumbing pipes and fixtures; the Earth has ~5,000 types of minerals.)

Copyright

Contributors

Supporting Program

Acknowledgements

This curricular unit was developed based upon work supported by the National Science Foundation under grant no. EEC 1542377—Grand Challenges for Engineering Focused RET with Stratified Teams, a collaboration of the College of Engineering at North Carolina State University, and the Control Optimization for Renewable Energies (CORE) Lab at the University of North Carolina at Charlotte. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.