Lesson Plan: Breaking Point!

Written By: Jolene Hermanson
Grade Level: 6

Time Allotment

2 weeks


Students will learn about the strength of certain geometric figures. They will use this information to design and build tables and bridges. They will discover the four different types of bridges built.


Subject Matter

Math, Science, STEM

Learning Objectives

  • Students will be able to identify the 4 different types of bridges.
  • Students will draw models of what they want their final design to look like.
  • Students will determine what geometric figure has the most strength.
  • Students will be able to use the engineering design process: ask, imagine, plan, create, and improve.
  • Students will become problem solvers, critical thinkers, and team players.
  • Media Components - Video/Web

  • Build a Bridge: http://prairiepublic.pbslearningmedia.org/resource/phy03.sci.phys.mfw.buildbridge/build-a-bridge/. This interactive activity from NOVA highlights the strengths and weaknesses of various bridge designs. It then challenges you to put your knowledge to the test by situating the right type of bridge in each of four different scenarios.
  • Tacoma Bridge: https://www.youtube.com/watch?v=3mclp9QmCGs
  • Why the bridges failed: http://www.pbs.org/wgbh/nova/tech/bridge-collapse.html
  • Materials

    • Tower building - 9 sheets of typing paper per group of 2 and tape
    • Table Top Build – 1 piece of cardboard 8 ½ inches by 11 inches, 4 pieces of newspaper, and 18 feet of duct tape per group of 2
    • Gum Drop Bridge- 100 toothpicks, 40 gum drops per group of 3 or 4

    Teacher Preparation

    • Cut out 8 ½ in by 8 in cardboard for table top
    • Count out toothpicks and gum drops for lab

    Introductory Activities

    (remember to number each step) 9 sheets of typing paper, tape

    Tower Building – test 3 columns of circular, triangular, and rectangular pillars. Make 3 pillars of each geometric shape.
    1. Start with making the 3 circular pillars.
    2. Place close together and test to see how many paperback books it can hold.
    3. Record your data.
    4. Next test the triangular pillars.
    5. Test to see how many paperback books it can hold and record the data. Lastly, make and test the rectangular pillars.
    6. Again record your data.
    7. Look at the data collected. Students should see that the circular shape is the strongest.

    Learning Activities

    8 ½ x 12 in cardboard, 18 ft duct tape, 4 sheets of newspaper

    Table Top – Design challenge for students. In group of 3 or 4 students challenge them to make a table top the is 8 inches tall using only 4 sheets of newspaper, 18 feet of duct tape, and cardboard. I give the tape 3 feet at a time.
    1. Decide on teams
    2. Draw a sketch in pencil of what you want the table top to look like.
    3. Hand out equipment. I would give student s rulers and scissors too.
    4. Teams have 45 minutes to build table.
    5. Any changes to the design must be noted in pen on your drawing.
    6. (usually the next day) test tables. It should hold 1 math book for 30 seconds.
    7. Test 2: See how many math books the table can hold. I do one table at a time and whole class watches. We record the data on the board. If there is a tie, I go by the table with the less weight.
    8. Discussion: Does your table look like a bridge?
    9. I show the video of the Tacoma Narrows Bridge failure and the 35 – W collapse.
    10. I also show pictures of the new 35-W bridge. It was built with lights that change color to make it beautiful. Why would an engineer build a bridge to that? I google to find the pictures. They are on my computer at work.
    11. We look at the top table to see what they did.
    12. Students can try building again to see if they can improve on their design.

    Culminating Activity

    100 toothpicks, 40 gumdrops

    Gum Drop Bridges
    1. Decide on the groups to build an arch gum drop bridge.
    2. Sketch what you want the bridge to look like.
    3. Hand out supplies. Bridge must span 6 inches in not touch the desk.
    4. Students have 45 minutes to build.
    5. When ready, they can test their bridge using rolls of pennies and nickels to test. As soon as they see it collapse, they can take the weight off. They go back to their area to redesign.

    Cross-Curricular Activity

    For this activity, I will take the class to the computer room. Build a Bridge: http://prairiepublic.pbslearningmedia.org/resource/phy03.sci.phys.mfw.buildbridge/build-a-bridge/

    Use the Nova Build a Bridge site to learn about the 4 different types of bridges. Do survey the sites, do your homework. In the do your homework, you will need 1 by 11 in cardboard strips, cut sponge with 4 hard cover books, and rope for the try it part. After done with do your homework, play the game.

    Community Connections

    We will have and engineering company visit the class to talk about how they make decisions when building projects.