Learning Objectives

After doing this activity, students should be able to:

• Understand the process of planning and gaining approval for projects
• Understand the importance of engineering in bridge design

Standards

Next Generation Science Standards

• Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem. [Grades 6 – 8]
• Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success. [Grades 6 – 8]
• Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions. [Grades 6 – 8]

International Technology and Engineering Educators Association

• E. Design is a creative planning process that leads to useful products and systems. [Grades 6 – 8]
• G. Requirements for design are made up of criteria and constraints. [Grades 6 – 8]
• G. Brainstorming is a group problem-solving design process in which each person in the group presents his or her ideas in an open forum. [Grades 6 – 8]
• I. Specify criteria and constraints for the design. [Grades 6 – 8]
• F. The selection of designs for structures is based on factors such as building laws and codes, style, convenience, cost, climate, and function. [Grades 6 – 8]
• I. Buildings generally contain a variety of subsystems. [Grades 6 – 8]
• J. Infrastructure is the underlying base or basic framework of a system. [Grades 9 – 12]

Common Core State Mathematics Standards

• Apply geometric methods to solve design problems (e.g., designing an object or structure to satisfy physical constraints or minimize cost).[Grades 9 – 12]
• Math Practice.MP7 – Look for and make use of structures.

National Council of Teachers of Mathematics

• Analyze properties and determine attributes of two- and three-dimensional objects [Grades 9 – 12]

Materials

Each group of 5 students will need:

• One sheet of 8 1⁄2 x 11” paper
• 100 pennies
• 2 books
• 1 Ruler
• 5 paper clips

Optional:

• Tape
• Up to 3 additional paper clips
• Scissors

Introduction

Begin with a brief explanation of construction and civil engineering. Explain the activity to the groups and begin passing out materials. Afterward, relate the activity back to engineering.

See educator guide for leading this activity in PBS Build It Big’s Paper Bridge design challenge.  The series’ interactive labs on forces, loads, and shapes offer a way to explore the physics of bridge construction.

Procedure

Overview: Teams will have monetary constraints for purchasing additional materials. Before beginning the project, teams must write down constraints and materials. Then they create two different ideas and designs. One of these designs must be approved by a “Do it To it” member before teams can begin purchasing items and creating their bridge. Each team receives $200 in Monopoly money. Prices are as follows:

• Scissors – $50
• Paper clips – $10 each
• Tape – $5 per 1” piece
• Paper – $100 per sheet.

Design challenge: The bridge must be designed in such a way that a modern car could drive through it. The area beneath the span must be free (so that boats can pass beneath it). To test the bridges, teams will place two books 20 cm apart and set the bridge on the books, spanning the gap. The bridge can not be fastened to the book (nor to any other support). Team members are allowed to place the pennies on their bridge in any desired way as long as the pennies are on the free part of the bridge.

Steps

1. Plan and design two different bridges
2. Gain approval from “Do it To it” member
3. Buy additional materials
4. Begin bridge-building process
5. Test bridge strength

Safety

Do not put the pennies in mouths or throw them. Scissors are for cutting given materials only.

Additional Resources

Bridge Basics A spotter’s guide and visual primer about the different types of bridge structures in Pittsburgh and Allegheny County, Pa.

Building Big PBS and WGBH Boston’s Design Squad series includes bridge-building challenges, interviews with civil engineers like Susan Knack, who rappels down bridges to inspect and repair them, and useful interactive labs that explain forces, loads, shapes, and materials.

Civil Engineering & Math Dr. Math, at Drexel University’s Math Forum, discusses how civil engineers use algebra, geometry, and calculus to figure out how big a column must be to hold a certain amount of weight to the time a batch of concrete must cure.

Common Core: A Lesson Plan on STEM (Bridges) K-8 technology teacher Jacqui Murray shows how to meet rigorous math and language-arts standards through the West Point bridge-building competition.

Garrett’s Bridges Designs and tips for constructing 28 types of bridges.

National Building Museum’s Bridge Basics. This 48-page educators guide includes activities and ways to demonstrate compression, tension, forces, and loads.

“The Big Bridge Scheme” – The Building and the Impact of the Brooklyn Bridge. This U.S. history lesson plan for grades 7 and 8 from the National Teacher Training Institute and New York’s Channel 13 includes a virtual reality tour of one of the country’s iconic structures.

Zoom Science (Season 4) Penny Bridge: Watch 11-year-olds construct a bridge from a single piece of paper that can hold 100 pennies. [YouTube 3:42]