# Bridging the Gap

### Summary

Students will explore the role that bridges play in our society. They will conduct an investigation to examine the various shapes and functions of bridges. They will determine which type of bridge would best suit a given scenario, and will give evidence to support this decision.

### Coin Type(s)

- Quarter

### Coin Program(s)

- 50 State Quarters

### Objectives

- Students will explore the role that bridges play in our society.
- They will conduct an investigation to examine the various shapes and functions of bridges.
- They will determine which type of bridge would best suit a given scenario, and will give evidence to support this decision.

### Major Subject Area Connections

- Language Arts
- Science
- Social Studies

### Minor/supporting Subject Area Connections

- Math

### Grades

- Fourth grade
- Fifth grade
- Sixth grade

### Class Time

**Sessions**: Five

**Session Length**:
45-60 minutes

**Total Length**:
151-500 minutes

### Groupings

- Whole group
- Pairs
- Individual work

### Background Knowledge

Students should have a basic knowledge of:

- Conducting science investigations in which inferences are made based on observations
- Cooperative learning
- Note taking

### Terms and Concepts

- Quarter
- Reverse (back)

### Materials

- 1 overhead projector (optional)
- What’s the Problem? page
- "Missing Bridge" Quarter page
- 1 class map of the United States
- Chart paper
- Markers
- Images of bridges such as those found at:
- 1 copy of an age-appropriate text that relates to bridges, such as:
- Bridges by Etta Kaner
- Bridges are to Cross by Philemon Sturges
- Bridges by Susan Canizares
- Bridges by Lynn M. Stone
- Bridges: Amazing Structures to Design, Build and Test by Carol Johmann

- "Building Bridges lab sheet
- Several books of identical thickness
- 4" x 6" index cards
- U.S. quarters
- Rulers
- Scissors
- Additional hardcover books
- String
- 2 chairs with backs
- 2 nine-foot pieces of rope
- Strong tape
- Heavy string
- 3' x 1.5' piece of cardboard
- "Bridge Basics" note-taking sheet
- 1 VCR and TV
- 1 copy of an age-appropriate video that provides basic information about bridges, such as:
- How Do They Build Bridges? Anchor Bay Entertainment, 1996. Approximately 30 minutes.
- Building Big—Bridges. WGBH Boston Video, 2000. Approximately 60 minutes.
- Awesome Bridges. Simitar Video, 1994. Approximately 12 minutes
- Structures (Bill Nye the Science Guy). Disney Educational Productions, 1995. Approximately 52 minutes.

- A reserved computer lab with Internet access
- Writing paper
- West Virginia Quarter Reverse page

### Preparations

- Make copies of the following:
- Building Bridges lab sheet (1 per student)
- Bridge Basics note-taking sheet (1 per student)
- 'Missing Bridge' Quarter page (1 per student)
- Make an overhead transparency (or photocopy) of each of the following:
- What’s the Problem? page
- "Missing Bridge" West Virginia quarter page
- West Virginia Quarter Reverse page

- Locate 1 copy of an age-appropriate text that relates to bridges (see examples under "Materials").
- Locate images of bridges (see example sources under "Materials").
- Assemble material trays for Session 2.
- Assemble quarters into groups (16 quarters per group).
- Assemble materials needed for Investigation #3
- Arrange to use a VCR and TV.
- Locate 1 copy of an age-appropriate video that provides basic information about bridges (see examples under "Materials").
- Arrange to use the school computer lab for one class period.
- Bookmark appropriate Internet sites.

### Worksheets and Files

Lesson plan, worksheet(s), and rubric (if any) at www.usmint.gov/kids/teachers/lessonPlans/pdf/328.pdf.

** Session 1**

- Display the "What’s the Problem?" overhead transparency and ask the students to discuss what they notice about this image. The students should point out the division of the communities by the ravine between them. Ask the students what might help bring these communities together. The students should respond that a bridge would make it easier to travel between the homes and the store.
- Ask the students to pretend that they are responsible for constructing a bridge to connect the communities. Invite them to consider the following questions: How would a bridge help this community? Who would use the bridge? Would the bridge be crossed by foot or by motor vehicle? What kind of material would be the best to use in building this bridge?
- Explain that, over the next few days, the students will be looking at different types of bridges and their functions and will decide which type of bridge would be most suitable for this type of crossing.
- Ask the students why we build bridges. Create a K-W-L chart and record student responses in the
**K**column of this chart to mark what the students**K**now about bridges. - Explain that the purpose of any structure is either to create a shape or create support. Based on that information, which one is the primary purpose of a bridge? The students should realize that a bridge is built as a means of supporting the individuals or machines that need to cross it. Add this information to the
**K**column as well. - Ask the students to contribute any other information that they may know about bridges. Add this information to the
**K**column also. - Remind the students that they will be looking at what type of bridge would be best for this situation. Ask the students to generate questions they need to ask to find out which type of bridge would be best. Guide the students’ questions so that they focus on how a bridge is built and why certain bridge structures are better than others. Show the students images of different types of bridges and famous bridges to help them generate their questions. Add student responses to the
**W**column of the K-W-L chart. - Introduce students to the related text about bridges.
- Read the selected text to the class and attend to any unfamiliar vocabulary.
- Explain to the students that they will be looking at three types of bridges. They will be testing two types of bridges in investigations, and watching a demonstration of a third kind.

**Session 2 **

- Describe the 50 State Quarters® Program for background information, if necessary, using the example of your own state, if available. Then display the transparency or photocopy of the West Virginia quarter reverse without the image of the bridge included. Locate West Virginia on a classroom map. Note its position in relation to your school’s location.
- With the students, examine the coin design. Have the students point out the elements of this design, including the river, the vegetation around the river, and the words "New River Gorge."
- Ask the students to define the word "gorge" based on this coin’s design. The students should realize that a gorge is a deep passage (in this case the passage holds a river) with steep, rocky sides.
- Ask the students what they can tell you about West Virginia based on the design of this coin. Answers should include that the state has very dense green vegetation, rolling rivers, and steep mountains.
- Explain that the quarter design is actually missing an image of a bridge. The bridge that actually crosses the New River Gorge is very important in improving travel within the state of West Virginia.
- Explain that, today, the students will break into small groups in which they will construct two types of bridges. The students will explore what happens to the structure when pressure is applied on the top of it.
- Distribute a "Building Bridges" lab sheet to each student and then divide the students into small groups of two or three. Direct the students to meet in their groups.
- Read through the lab sheet as a class and answer any questions about the students’ responsibilities during this investigation.
- Model the students’ first investigation problem to show how they will construct a beam bridge.
- Direct each group to gather a materials tray, follow the directions on the lab sheet, and answer the first set of questions listed under "Investigation #1."
- Once the students have all completed the first investigation, model the students’ second investigation problem to show how they will construct an arch bridge. Direct them to read and complete the remainder of the investigation activities.
- Direct each group to follow the directions on the lab sheet and answer the first set of questions listed under "Investigation #2."
- As the students complete the investigations, direct them to compare the two bridges (beam and arch) with their lab partners.
- Have the students file their "Building Bridges" lab sheets for use at a later time.

**Sessions 3 and 4 **

- Revisit the bridge-building activity from the previous session. As a class, discuss what the students learned about the bridges. Ask the students which of their models held the greatest amount of weight over the longest distance. Have the students discuss which of their questions from the K-W-L chart were answered by these activities. Add student responses to the
**L**column of the chart. - Tell the students that, today, they will see a demonstration of Investigation #3, the third type of bridge, a suspension bridge. Explain that the experiment will be demonstrated to the class and that four student helpers will be needed.
- The students should take out their "Building Bridges" lab sheets to record the findings of the demonstration under "Investigation #3."
- Explain to the students that the third bridge investigation is more complicated than the other two. It requires more steps, time, and materials. Solicit four student volunteers. Have the other students follow along in their lab sheets as you set up, explain, and conduct the investigation for a suspension bridge. Tell them that a suspension bridge operates much like this example. Two towers (the chairs) support cables (the rope) that are anchored at each end. The roadway (the cardboard) is suspended from these cables.
- Conduct the investigation and, from the class discussion, have the students fill out their lab sheets. Provide enough time for them to create their drawings of the investigation.
- Review the discussion from Session 2 about the beam and arch bridges with the students. Discuss the strengths and weaknesses of the suspension bridge as well.
- Direct the students to complete the "Investigation" question on their lab sheets.
- Introduce the students to the selected video about bridges.
- Distribute a "Bridge Basics" note-taking sheet to each of the students. Explain that, as the students watch the video, they will need to take notes about the different types of bridges that exist and how engineers choose a specific type of bridge.
- As a class, view the selected video. After the viewing, attend to any student questions or concerns.
- Direct the students to use the information from this video to amend their responses to the "Investigation" question on their lab sheets if necessary.
- Review all the material presented in the investigation and video. Have the students discuss which of their questions from the K-W-L chart were answered by this video. Add student responses to the
**L**column of the chart. - Tell the students to file their "Bridge Basics" note-taking sheets for use at a later time.

**Session 5 **

- Lead a discussion about the three investigations. Have the students reflect on the various parts of each investigation. They should review and discuss items such as the amount of time, materials, and people needed to complete the task.
- Have the students discuss the strengths and weaknesses of the three bridge types. Responses should reflect that both the arch and suspension bridges can span longer distances. The suspension bridge takes the longest to build, costs the most, and requires the most materials. The beam bridge is the most basic type of bridge, requiring very little time and materials.
- Direct the students to get with a partner and think about all of the new information that they have learned about bridges and the area surrounding the New River Gorge. Based on the information the students have collected on their "Building Bridges" and "Bridge Basics" sheets as well as the information listed on the K-W-L chart, the students should make a final decision about what kind of bridge they feel would work best for crossing the New River Gorge.
- Distribute a photocopy of the ‘Missing Bridge’ page and the "`Missing Bridge’ Quarter" page to each student.
- Direct each student to complete the West Virginia quarter design by drawing his or her selected bridge type on this image. On a piece of writing paper, have each student write an explanation for why he or she believes his or her selected type of bridge would work best in this scenario. The students should use information from their investigations and research to support this choice.
- After all papers are written and collected, display the actual West Virginia quarter design for the students.
- Have the students identify the type of bridge displayed on this coin. Ask the students how many of them thought that an arch would be the best choice for this bridge.
- As a class, discuss why this is an appropriate bridge type for this situation and have the students justify their conclusions. Direct the students to include in their final response reasons that the other types of bridges would not be appropriate bridge options for this site.

### Differentiated Learning Options

Provide students with a vocabulary list of key bridge terms to assist with their investigation.

### Enrichments/Extensions

- Introduce students to the terms "compression" and "tension" in relation to bridges. Use these terms when discussing the way the bridge reacts to the weight being placed upon it.
- Invite students to explore the bridge that is shown on the Rhode Island quarter. They should investigate what type of bridge this is, where this bridge is located, and express why this type of bridge was selected rather than a different type.

Use the worksheets and class participation to assess whether the students have met the lesson objectives.

**Discipline**: Math

**Domain**: 4.MD Measurement and Data

**Grade(s)**:
Grade 4

**Cluster**: Solve problems involving measurement and conversion of measurements from a larger unit to a smaller unit

**Standards**:

**4.MD.1.**Know relative sizes of measurement units within one system of units including km, m, cm, kg, g, lb, oz, l, ml, hr, min and sec. Within a single system of measurement, express measurements in a larger unit in terms of a smaller unit. Record measurement equivalents in a two column table.- For example, know that 1ft is 12 times as long as 1in. Express the length of a 4ft snake as 48in. Generate a conversion table for feet and inches listing the number pairs (1, 12), (2, 24), (3, 36), ...

**4.MD.2.**Use the four operations to solve word problems involving distances, intervals of time, liquid volumes, masses of objects, and money, including problems involving simple fractions or decimals, and problems that require expressing measurements given in a larger unit in terms of a smaller unit. Represent measurement quantities using diagrams such as number line diagrams that feature a measurement scale.**4.MD.3.**Apply the area and perimeter formulas for rectangles in real world and mathematical problems. For example, find the width of a rectangular room given the area of the flooring and the length, by viewing the area formula as a multiplication equation with an unknown factor.

**Discipline**: Language Arts

**Domain**: All Language Arts Standards

**Cluster**: Use of Spoken, Written, and Visual Language

**Grade(s)**:
Grades K–12

**Standards**:

- Students use spoken, written, and visual language to accomplish their own purposes (e.g., for learning, enjoyment, persuasion, and the exchange of information).

**Discipline**: Science

**Domain**: 5-8 Content Standards

**Cluster**: Physical Science

**Grade(s)**:
Grades K–12

**Standards**:

- Properties and changes of properties in matter
- Motions and forces
- Transfer of energy

**Discipline**: Science

**Domain**: 5-8 Content Standards

**Cluster**: Science as Inquiry

**Grade(s)**:
Grades K–12

**Standards**:

- Ability necessary to do scientific inquiry
- Understand scientific inquiry

**Discipline**: Language Arts

**Domain**: All Language Arts Standards

**Cluster**: Applying Strategies to Writing

**Grade(s)**:
Grades K–12

**Standards**:

- Students employ a wide range of strategies as they write and use different writing process elements appropriately to communicate with different audiences for a variety of purposes.

**Discipline**: Language Arts

**Domain**: All Language Arts Standards

**Cluster**: Effective Communication

**Grade(s)**:
Grades K–12

**Standards**:

- Students adjust their use of spoken, written, and visual language (e.g., conventions, style, vocabulary) to communicate effectively with a variety of audiences and for different purposes.

**Discipline**: Social Studies

**Domain**: All Thematic Standards

**Cluster**: People, Places, and Environment

**Grade(s)**:
Grades K–12

**Standards**:

Teachers should:

- Enable learners to use, interpret, and distinguish various representations of Earth such as maps, globes, and photographs, and to use appropriate geographic tools
- Encourage learners to construct, use, and refine maps and mental maps, calculate distance, scale, area, and density, and organize information about people, places, regions, and environments in a spatial context
- Help learners to locate, distinguish, and describe the relationships among varying regional and global patterns of physical systems such as landforms, climate, and natural resources, and explain changes in the physical systems
- Guide learners in exploring characteristics, distribution, and migration of human populations on Earth’s surface
- Have learners describe how people create places that reflect culture, human needs, current values and ideals, and government policies
- Provide opportunities for learners to examine, interpret, and analyze interactions of human beings and their physical environments, and to observe and analyze social and economic effects of environmental changes, both positive and negative
- Challenge learners to consider, compare, and evaluate existing uses of resources and land in communities, regions, countries, and the world
- Direct learners to explore ways in which Earth’s physical features have changed over time, and describe and assess ways historical events have influenced and been influenced by physical and human geographic features