Using Math to Build Bridges

Megan Walker

Unit Title:
Using Math to Build Bridges

Grade Level:
Grade 7

Subject Area:

Total Estimated Duration:
18 Days (60 minute)

Using Math to Build Bridges

Bridge Poster

Unit Lessons:
Lesson 1: The Bridge Challenge
Lesson 2: Angles, Scale Factors and  Bridge Design
Lesson 3: Bridge Design Challenge   

Background Knowledge:
Successfully understand the concepts in the unit students must be aware of how to set up a proportion of any kind. They must also understand the concept of percentages and how those can relate to proportions. The last thing that students will need in order to grasp the concepts in the unit are social, interaction skills for completing projects with peers.

Additional Resources:                  
Ohio RC
Brent Spence Bridge
Urban Cincy

February 2013

The Big Idea (global relevance)

The big idea of the unit is: How is math used in the building and engineering of infrastructures? Students have traditionally struggled with when and how they can use proportions to solve real life problems, and proportions can be used in so many ways. So with bridges they will inquire about scale factors used to build them, angles used in the structure, and percentages of building materials.

Essential Questions
  1. What are the specific qualities that go into engineering a safe and efficient bridge?
The Challenge

In the news today there is a lot of emphasis on the infrastructures in the world. The infrastructures we have may still be, or at some point were structurally sound, but are beginning to deteriorate or are lacking in some design features. The challenge for the students will be to explore design features and safety of infrastructures such as bridges, and apply what they learn to making them better. Students will explore the design options to meet requirements for loads, safety, and traffic flow as well as the efficiency of these structures for various capacities. 

The Hook

The hook will be giving the students some information in the news regarding the situation with the Brent Spence Bridge. I will use this site to help facilitate this interest:

Also, the video I created for the unit will be used as an overall related hook.

Guiding Questions
  1. What types of angles allow for more support for the structure?
  2. How will you use scale models, and scale factors to create your bridge as a model for the Brent Spence Bridge?
  3. How can percentages come into play for the load or support of the bridge?
  4. What types of materials will you need to construct an improved model of the Brent Spence Bridge?
  5. What types of structural changes would you make to construct an improved model of the Brent Spence Bridge?
  6. How will you know if the model you have designed would meet requirements/needs?
ACS (Real world applications; career connections; societal impact)

The issue of today’s deteriorating infrastructures is an issue that surrounds all of us. This unit on the use of math and science involved in building/engineering bridges is relevant to the importance of efficiency and safety of the bridges we use to cross our water ways, specifically one close to home: The Brent Spence Bridge. Students will gain an understanding of how engineers must use scales, percentages, angle measures, and proportional relationships to consider the efficiency and safety of the bridge they constructing. The student will gain an understanding of how the math processes they are going through will relate to certain careers in the real world, such as engineers. There are societal issues related to the building of bridges. If bridges are not built properly then the safety of the people using it are at risk, having a huge impact on many lives.

Engineering Design
  1. Research requirements for the Brent Spence Bridge in Cincinnati.
  2. Design ways to improve upon the bridge.
  3. Develop ways to build a model of the redesigned bridge.
  4. Research ways to construct the model bridge.
  5. Construct the redesigned model.
  6. Test the model’s strength/efficiency.
  7. Provide results of strength of bridge comparing percentages to others results.
  8. Present results of conclusions.
Unit Academic Standards & Assessments
  1. Analyze proportional relationships and use them to solve real-world and mathematical problems.
  2. Use proportional relationships to solve multi-step ratio and percent problems. Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error.

  3. Draw, construct, and describe geometrical figures and describe the relationships between them.
  4. Solve problems involving scale drawings of geometric figures, including computing actual lengths and areas from a scale drawing and reproducing a scale drawing at a different scale.

  5. Solve real-life and mathematical problems involving angle measure, area, surface area, and volume.
  6. Use facts about supplementary, complementary, vertical, and adjacent angles in a multi-step problem to write and solve simple equations for an unknown angle in a figure.

  7. Apply the steps of the design process to solve a variety of design problems.
  8. List the seven steps of the design process and explain the activities that occur during each phase.