# Lesson: Engineering 101

Authors: Peter Anderson, Wade Goodridge, Sarah Lopez, Natalie Shaheen

## Class Size

• Originally written to be taught to a class of 10 students, working in groups of 3-4.
• Could expand to 15-20 students without modification or even larger if an assistant is available to help monitor groups’ progress.
• Could scale down to 2-3 students, working as a single group, as written. With 1 student, modifications should be made to minimize the tedious measurement processes in the Cheetos activity.

## Lesson Structure

120 minutes

• Cheetos criteria and constraints: 30 minutes
• [Engineering Example] Engineering: 70 minutes
• [Engineering Example] Improvement: 20 minutes

## Objectives

Students will be able to:

• Discover criteria and constraints by measuring manufactured objects.
• Measure length and mass of irregular objects.
• Analyze a table of results to determine patterns.
• Differentiate between science and engineering in terms of their practices and foci.

## Prerequisite Knowledge

• Experience measuring with a scale and ruler
• Experience using a talking LabQuest (optional)

## Accessibility

• Click rule
• Talking scale
• Tray of materials helps keep students organized

## Materials

All materials are listed on a per student basis unless otherwise noted.

• Cheetos Criteria and Constraints (one of each per group of 3-4 students)
• 10-30 Cheetos (<1 oz)
• Click rule
• Talking scale
• A precision scale, such as the one in the LabQuest product line is ideal.
• Accessible calculator
• Writing utensils (such as 20/20 markers, or Brailers and paper)
• Optional: Cafeteria tray or half baking sheet to contain all materials
• Engineering Example
• Materials will depend on activity used.

Note: Refer to Accessible Lab Equipment & Instructional Materials for additional information regarding specialized tools/materials.

## Preparation

1. Setup each lab station with all materials listed for Cheetos activity.

## Procedure

### Cheetos Criteria and Constraints

1. Introductory material.
• Tell. “In your imagination the limits are boundless and the combinations are endless. This is a useful way to think. It is the realm of philosophers, artists, and responsible for a good portion of civilization’s progress. Great ideas are born this way. As ideas mature, the limits become more real and the possible combinations decrease in number.”
2. Criteria definition.
• Tell. “Engineers help ideas mature and take shape. Engineers design under criteria and constraints. A criteria is a positive, specific statement of what a product must do. They are the parts of the original idea you keep through to the end.”
3. Criteria example - smartphones.
• Tell. “For example, think about a smartphone. This device started by someone saying, ‘I want a computer that I can hold in my hand that can play music, games, search the internet, take pictures, and make phone calls almost instantly.’”
4. Constraint definition.
• Tell. “A constraint is a limiting characteristic. They are the real-life boundaries of what is possible and informed by technology, time, and money. As many artists will tell you, having boundaries improves creativity.”
5. Constraint definition - smartphones.
• Tell. “A smartphone is limited by the electrical components, batteries, size of the human hand, and what people will pay.”
6. Cheeto introduction.
• Tell. “We are going to look at something engineered and work backwards to figure out what their criteria and constraints were. We will accomplish this through observation. Every product that you buy has criteria and constraints associated with it. The humble Cheeto will be our first subject.”
7. Set up groups.
• Do. Help students organize into groups of 3-4. Give each group a pile of Cheetos and a set of materials (as listed in the materials section).
• Note: The length of this portion will be largely dependent on how many Cheetos each group needs to measure. Depending on how much time you want to spend, and how efficient your students are, you may want to give each group anywhere from 5 to 20 Cheetos. Ideally, have students only make measurements of unbroken Cheetos.
8. Demonstrate the process.
• Teach. Use the materials while narrating the process.
• Measure each Cheeto in its longest dimension. Record the data.
• Measure the mass of each Cheeto by weighing it. Record the data.
• Calculate the average of the length data and the average of the weight data.
9. Process.
• Tell. “We are going to do this quickly and to do that we will use an assembly line process. Take a Cheeto, weigh it, write it, measure its length, write it down, eat it. Make sure each person in your group has a task to make this process efficient.”
10. Perform the activity.
• Do. Direct students to begin. After students complete the process, have them calculate the averages and find the highest and lowest data points for both length and weight.
11. Facilitate the data share out for weight.
• Do. Record this data in case it needs to be repeated. Ask one member of each group to report:
• Average weight
• High weight
• Low weight
12. Discussion.
• Ask. “Does anyone see any patterns in the data?”
• Tell. “Unbroken Cheetos are between 0.97 and 1.03 grams unless they have broken in the bag. This is a criteria for Cheetos because it is a statement of what a Cheeto must be.”
13. Facilitate the data share out for length.
• Do. Record this data in case it needs to be repeated. Ask each group’s Cheeto chief to report:
• Average length
• High length
• Low length
14. Discussion.
• Ask. “Does anyone see any patterns in the data?”
• Tell. “Cheetos are no more than 3 inches long. This is a constraint because it is a statement of what a Cheeto can’t be or a limit on the Cheeto.”
15. Reason for constraints.
• Ask. “Why do you think that Cheetos need to be fewer than 3 inches long?” Avoid choking in children, fit into a bag without breaking, getting stuck together, fall through the funnel that loads them in the bags in the manufacturing process, etc.
• Note: Plausible answers are any constraint that the engineers might face. Don’t rush this discussion, as students will often have really great and unique answers when given time to think.
16. Explain the weight criteria.
• Tell. “One reason that Cheetos have to be such a carefully controlled mass has to do with cooking time. Regardless of their shape, to achieve the crunch without burning requires that they be cooked to a very specific level. If they are too big or small they will cook too slowly or too quickly.”
17. Full picture.
• Tell. “When designing technology, criteria and constraints help the engineer decide on the shape, size, materials, and process used to create it. In this case they inform the Cheeto recipe, how it gets made in the factory, cooked, quality controlled, bagged, transported, and eaten safely. An engineer has to think about the entire product’s life cycle, not only the crunch.”
18. Conclusion.
• Tell. “You will be working as engineers throughout this project. Requirement analysis, or the process of determining criteria and constraints, is a really key part of the engineering design process, and is a step that engineers spend a lot of time on. To see how important this is, imagine spending weeks, months, or even years perfecting a design, only to find out at the end that your design won’t work because it cannot meet one of the constraints. Be sure you know clearly what the criteria are and figure out any constraints before beginning your work.”

### Example Engineering Activity

Include an activity that requires students to engage in the engineering process by brainstorming a solution to a problem; building, testing, and evaluating that solution; and improving on it to make a better solution. Students should be presented with a hypothetical scenario that requires a solution to be designed. The criteria and constraints for the design should be clearly explained. There should be tradeoffs within the design process such that a ‘perfect’ design is impossible, but students must decide which qualities and features to prioritize (for example, minimize cost, but maximize strength). Once students determine their design, they should be able to build a model of it and test it. Test results should be a number, rather than a simple pass/fail. The results of their tests can then be combined with the ‘cost’ of their design choices to determine their overall score. Once students have their first score, they are given a chance to change their design however they see fit in order to hopefully improve their design. After modifying their design, they will build, test, and score their new design and compare it to their first design.

In this lesson as originally written, a highly simplified version of the Stick in the Mud activity from the Engineering Is Elementary curriculum from the Boston Museum of Science was used, but another activity could be easily substituted. If using the Stick in the Mud activity, you can remove the parts about the river moving over time, the parts about empirically determining the effect of compaction on soil, and any other parts that do not directly support the learning outcomes listed below. Further information and ideas about the original activity can be found at https://eiestore.com/a-stick-in-the-mud-evaluating-a-landscape.html

The key learning outcomes of the lesson are:

• Understanding that engineering tries to solve a problem (as opposed to science, which is primarily seeking information, not solutions).
• Learn and practice the steps of the engineering design process:
• Ask – What is the problem? What do I know about the scenario? What kind of solution is needed?
• Imagine – How could you meet the requirements of the project?
• Plan – Decide how you will solve the problem and make your design
• Create – Build a real model of your design. Test your model and see how well it meets the criteria and constraints.
• Improve – How could you change your design to make it better? Make changes and try out your new design.
1. Scientist/Engineer Motivation.
1. Tell. “Scientists and engineers do their work for different reasons and purposes. A scientist tries to figure out how the world works or the effect that changing one variable has on another variable. For example, they may seek to understand a process such as how stars generate all the elements we have available. An engineer tries to use their knowledge about the world to change, improve, or create something. An engineer doesn’t just want to know how something works, they want to know how to make it work better.”
2. Introduce the design cycle.
1. Tell. “When engineers work to solve a problem they use a process. They ask questions, imagine solutions, make a plan, create and test that plan, and then make improvements. Then they repeat the process. Each cycle refines the design more and more until the problem is solved or some other limit is reached (time, money, available materials, etc.)”
3. Perform the activity.
1. Insert your chosen activity here!
4. Perfect score discussion.
1. Ask. ”What would the perfect score for this project be? Is it possible to get that? What do you think is the best realistic score?”
2. Do. Take several responses.
5. Review the design cycle.
• Teach. Review the design cycle, spelling out the parts:
• Imagine - we thought up our designs.
• Plan - we decided a lot of things and decided the specifics of our plan.
• Create - we made one and tested it.
• Improve - we tried one, scored it, and then tried again.
6. Review the point of the activity.
• Tell. “Scientists and engineers have different motivations. Scientists use experiments to understand and learn about our world. Engineers design something that will benefit humankind. Engineers use knowledge that scientists learn. Scientists use the designs that engineers make.”

## Standards Alignment

NGSS Standards Alignment:

• SEP 1, SEP 4, SEP 6, CCC 1, CCC 4, HS-ETS1-3, HS-ESS2-6

CCSS Standards Alignment:

• CC.9-10.R.ST.3, C.9-10.R.ST.5, CC.9-10.R.ST.7, CC.9-10.R.ST.3, CC.11-12.R.ST.3, C.11-12.R.ST.5, CC.11-12.R.ST.7, CC.9-12.S.IC.4, CC.9-12.S.ID.3