STEM Challenge – Building Bridges

Grade Level: 6th Grade
Subject: STEM / Engineering / Physical Science
Duration: 60 Minutes

Objective:

By the end of this lesson, students will be able to apply basic engineering principles and collaborate to construct a freestanding bridge structure using limited materials. They will evaluate the strength and stability of their designs and reflect on how engineers solve real-world problems through teamwork and iteration.

Materials:

• Index cards or paper strips

• Masking tape (a small roll per group)

• Paper cups or small objects to use as weights

• Books or two desks/chairs to serve as “bridge supports”

• Whiteboard or chart paper for whole-class discussions

• Timer or stopwatch

Lesson Plan Outline

1. Engagement Activity: Real-Life Bridges (10 Minutes)

Say: “Today we’re going to become engineers! Engineers solve real-world problems—like designing bridges that carry people and vehicles safely across rivers, roads, or canyons.”
Do: Show images of iconic bridges (Golden Gate Bridge, London Bridge, rope bridges). 

Ask: “What do you notice about their shapes?” and “Why do you think some bridges use triangles in their designs?”

Discuss: Talk briefly about balance, tension, and stability. “Engineers have to think about all these forces when designing bridges.”

 Ask: “What do you think makes a bridge strong?”
 

2. Instruction and Demonstration: The Engineering Design Process (10 Minutes)

Say: “Today, your challenge is to design and build a bridge using paper and tape. Your bridge must span two ‘cliffs’—represented by two books or desks—12 inches apart. The goal is to make a bridge strong enough to hold the most weight (paper cups filled with small objects).”

Do: Review the Engineering Design Process on the board:

1. Ask – What is the problem?

2. Imagine – Brainstorm ideas.

3. Plan – Sketch and list materials.

4. Create – Build your structure.

5. Test – Does it work?

6. Improve – How can you make it better?

Say: “There are no wrong answers—just solutions to test! Engineers often improve their ideas through trial and error.”

3. Guided Practice: Group Planning (10 Minutes)

Do: Divide the class into small groups of 3–4 students.

Say: “First, brainstorm and draw a plan. Think about how to make your bridge stable. Will you fold the paper? Roll it? Make columns?”

Ask: “What shapes or patterns will give your bridge strength?” (Prompt students to think about arches, triangles, and folded structures.)

Do: Encourage creativity and remind students to assign roles: planner, builder, recorder, and tester. Set a timer: “You have 5 minutes to plan, then 10 to build.”

4. Independent Practice: Build and Test (20 Minutes)

Do: Let students begin building. Walk around to ask open-ended questions:

• “Why did you choose this design?”
   

• “How will you test it?”
   

• “What challenges are you facing?”
   

Do: After 10–12 minutes, initiate testing. One group at a time places their bridge between two books and slowly adds cups or weights until the bridge fails or reaches its max capacity.

Optional (Time Permitting): Allow groups to revise and retest once.

5. Reflection and Wrap-Up: Engineering in Action (10 Minutes)

Do: Circle back as a whole group. Ask:

• “What strategies worked best?”
   

• “What did you change during the process?”
   

• “How do engineers in the real world learn from their mistakes?”
   

Say: “Engineering is about persistence, problem-solving, and teamwork. Every bridge you made today taught you something new—and that’s exactly what engineers do!”

Formative Assessment

• Observe group collaboration, planning, and participation.
   

• Listen for vocabulary use (e.g., “support,” “balance,” “test”).
   

• Use a simple exit prompt: “One thing I learned today about bridges is…”
   

Differentiation Strategies

• For early finishers: Ask them to redesign a new bridge using only half the materials.
   

• For students with IEPs or learning differences: Allow verbal instead of written planning; assign supportive roles during group work (e.g., builder instead of planner).
   

• For ELLs: Use visual examples of bridge shapes and label design process steps on the board with drawings.
   

Example Demonstration: Teacher-Student Script (Mini-Lesson)

Teacher: “Okay, team, let’s look at this strip of paper. If I just lay it flat, it bends easily, right? But what if I fold it like an accordion?”

(Demonstrates folding and placing it across two books)

Teacher: “Now let’s test—how many paper clips can it hold before it bends?”

Student: “Whoa, it’s holding more!”

Teacher: “Exactly! That’s what engineers do—they find ways to make materials stronger without adding more materials. You’ll need to think like that too during your challenge!”

Written by Rachel Jones
Education World Contributor
Copyright© 2025 Education World