Mind the Gap

Marshmallows with blue dots…an activity that gets the message across

Contributed by: Gordon Webb

Grade 7: Structures and Mechanisms

  • Structures have a purpose.
  • The form of a structure is dependent on its function.

Inquiry Skills Used

Initiating & Planning: brainstorming

Performing & Recording: drawing the design of the bridge

Analyzing and Interpreting: testing the soundness of the structure and drawing conclusions based on information gathered

Communicating: visual, written and oral communication

Safety Considerations

Students should be careful when handling sharp toothpicks.


Engineers are people who design and make things.  Structural engineers design, build, and test things that have to do with structures. They often research various shapes for their designs, as well as the interrelationships between these shapes and the integrity of the structure.  They must also assess how various materials will function to make the structure more sound.  In the designing stage, engineers consider several things: the task (what they are being asked to build), the parameters and size of the structure (how long/strong/tall it must be), and can the structure be built in a cost effective way (cost/durability of the materials being used).

What You Need

  • Toothpicks
  • Miniature marshmallows
  • 5 quarters in a paper cup
  • Round tipped scissors
  • Paper and pencils
  • 2 chairs
  • Erasers and rulers

What to Do

  1. The students will be building a bridge to cross a gap.
  2. The design must be at least 30 cm long and must hold a container holding a specified weight.
  3. Set up chairs 30 cm apart from each other.
  4. Students are directed to create a bridge that must bridge the gap between chairs.
  5. Brainstorm about concepts of good engineering practices: understand the problem, design, build a model, and test.
  6. Discuss the types of problems that could be encountered during this exercise.
  7. Explain to students that they will be using the engineering cycle to build their bridges.
  8. Explain the challenge and the expectations of the outcome.

Summary Notes

All engineers use similar processes to resolve a given problem. The steps in the process are as follows:

1.) Understand the Problem:  they first must make sure they understand the problem or challenge.

2.) Design a Solution: draw a design of their resolution to the problem on paper.

– consider things such as the parameters of the task

– materials to use

– cost of materials.

3.) Build a Model: build a model (a smaller version) of the project to test it and see if it works.

4.) Test & Retest: test the models and assess.  They may need to redesign and fix any inadequacy.

5.) Repeat.

Where to Go from Here?

Any materials can be used. A larger structure could be constructed using dollar store meat skews and hot glue guns. The students could build suspension bridges with string and popsicle sticks. The students could be challenged to make a larger structure using different materials.    The students could explore the effects of outside forces acting on the bridge (e.g., wind, earthquakes, expansion and contraction from changes in temperature).

STSE Links

How might this information influence the design and appearance of a structure, the materials it is made from, and so on? What things might a company need to take into account when considering the construction of a new structure that consumers might not consider (e.g., the environmental impact of using certain resources to make the structure, the eventual disposal of the structure)?

Write a newspaper article that identifies the factors that caused a structure to fail and the impact it might have to the human and natural environment.

Cross Curricular Connections


  • Write the design plans for a structure that will support a given load.  Include labelled diagrams, materials list, and procedural instructions.  Add any revisions needed to effectively design the structure.
  • Write a newspaper article that identifies the factors that caused a structure to fail and the impact it might have to the human and natural environment.



  • Design, construct, and use physical models to investigate the effects of various forces on structures (Number Sense and Numeration: ratio, Measurement: scale drawings, etc.).
  • Describe the role of symmetry in structures (indirectly, Geometry- reflection).

Visual Arts

  • Draw and label a diagram that shows both the external forces and internal forces acting on a structure.





I’m the Queen/King of the Castle

Contributed by: Gordon Webb

Grade 1: Structures and Mechanisms


  • An object is held together by its structure.
  • The materials and structure of an object determine its purpose.

Inquiry Skills Used

This is a hands-on activity with students exploring and experimenting to produce a structurally sound building using various materials.

Safety Considerations

Students should be reminded about safe practices regarding the use of scissors.


Structures can be made from various materials.

The soundness of the structure is dependent on how these materials are made into various structures and used in combination to create a solid structure.

What You Need

  • Straws
  • Bamboo cooking skews
  • Coloured tissue paper or other thin paper
  • Scissors
  • Glue, tape or staples
  • Toilet/paper towel rolls
  • String
  • Construction paper
  • Templates of a cone, rectangular prism, cylinder
  • Corrugated cardboard for a base


What to Do

1. Start by reading a story about different types of castles to the class.

2. Brain storm with the class about which shapes can be       used in a castle.

  • cone and cylinder make a tower
  • a rectangular prism makes a keep or a wall

This activity can be done individually or in groups.

3. Distribute the materials to the class.

4. Demonstrate how to convert a cone and cylinder into a wall tower.

5. Have the students explore how to connect the towers and how the occupants of the castle will get in and out of the castle.

6. Provide an example of a pre-made castle, using the various components, or demonstrate using pictures.

Where to Go from Here?

Students can learn more about structures of a castle in the following websites:



Have the students explore the following:

  • What is the purpose of your structure?
  • What materials did you use to build your structure?
  • Why did you choose those materials instead of _____ to build your structure?
  • What did you use to fasten your structure together?
  • What might happen to the materials in your structure when it is no longer being used?

STSE Links

Discuss with the students the various materials used to build houses and which would be stronger or more durable.

Cross Curricular Connections


  • The teacher can combine this activity with literacy, reading the story, The Three Little Pigs or Three pigs, A Wolf and Seven Magic Shapes by Grace Maccarone, and comparing the materials used to build the various structures.


  • The structures can be made of three-dimensional shapes.


Internal and External Forces and The Three Little Pigs

archBy Susan Ibdah

This paper outlines a cross-curricular lesson between Science and Language Arts. The focus is internal forces and external forces acting on structures. Students will apply their knowledge of forces and stabilization to build houses in the context of the True Story of the Three Little Pigs. Continue reading

Learning from Nature: Bio-Mimicry

Solar Ivy:  SMIT (2013)

Solar Ivy: SMIT (2013)

By Allison Dow

Throughout the grade 7 Form and Function Unit, students have the opportunity to explore and experiment with the various types of structures and mechanisms that humans have designed and modified throughout time. While many of these structures have proved to be grand advancements making our lives easier and more efficient, we often overlook the innovations that nature has been developing and evolving for millions of years. Bio-mimicry is an area of study and design that uses the inspiration of naturally-occurring elements to meet many of our design challenges in a highly effective manner. This area within science is currently receiving much attention as biology proves to have already solved many of our human predicaments.

Some simple examples of Bio-mimicry include solar, ivy-like, solar panel leaves from the company Sustainably Minded Interactive Technology (SMIT). Sharklet™ Surface Protection has mimicked the dermal denticles on shark skin which resist bacterial growth, to create adhesive-backed skins that can be placed on high-touched areas such as door handles to effectively reduce spread of bacteria and viruses (InterfaceFLOR). Additionally, wind turbines, bathing suits, submarines, and many aviation and robotic designs have emulated the highly effective approach that nature has taken to solve its own design challenges such as running quickly over rough terrain as seen in cockroaches, water-resistant cuticles on plant tissue leaves, and infra-red detecting sight in many insects.



Lesson Challenge

Students will be challenged to meet a design challenge either in our society or a third world society that meets a current human need in a sustainable way. Students will be encouraged to look for a design pattern found in nature that could be applied to create an effective and efficient human tool, mechanism, or structure. They will have access to recyclable materials as well as common green mechanisms like small solar panels, and any additional tools required for building, such as string, tape, nails, and hammers.

In groups of 2-3, students will meet their design challenge by:

  • Identifying a need in either our society or in a society of need
  • Proposing their bio-mimicry concept to the class in request for constructive and positive feedback
  • Developing a blue-print design with required materials for their innovative mechanism
  • Creating a working prototype of their mechanism
  • Delivering a marketing presentation on their product to the class

Success Criteria

  • Students identify a unique design challenge that can be met by bio-mimicry
  • Students use recycled materials or energy conserving materials
  • Students work cooperatively as a team while supporting the design process of other groups
  • Students accurately identify the form and function concepts from the unit to their product
  • Students are able to identify the benefits and drawbacks of their product economically and environmentally.

Time Required

This culminating design challenge activity will take a class period to complete effectively in order to meet the success criteria and allow students the time to construct a working model.


The materials required for each group to develop their own product will depend on the design and intended function of that product. Save recyclable products from your house and classroom so that students can begin the design process and bring in any additional required materials from home. Sheets of malleable plastic and small, re-usable solar panels can be ordered from science supply stores and will not take too much of the funds from your Science budget.

Additional Challenge

Dragon’s Den/Shark Tank TV Show style
Provide each member of your class with fake money that they can use to invest in the product of their choice. They cannot simply choose to invest in their own product but must choose from one of the other groups. Have students prepared to ask questions about their target market and marketing strategies. The top three groups can have a picture with their bio-mimicry product and their write up and blue-print posted on the class bulletin.

Supporting Available Resources

  1. You Tube Video: Bio-Inspiration: Nature as Muse – KQED QUEST:
  2. You Tube Video: Biomimicry and Landscape Architecture:
  3. TED Talks: Janine Benyus: The promise of biomimicry:

Grade 7 Overall Expectations Met

Science: Form and Function
1. analyse personal, social, economic, and environmental factors that need to be considered in designing and building structures and devices;
2. design and construct a variety of structures, and investigate the relationship between the design and function of these structures and the forces that act on them

Geography: Natural Resources
• use a variety of resources and tools to gather, process, and communicate geographic information about the distribution, use, and importance of natural resources;
• describe positive and negative ways in which human activity can affect resource sustainability and the health of the environment.

The Arts: Visual Arts
D1. Creating and Presenting: apply the creative process (see pages 19–22) to produce art works in a variety of traditional two- and three-dimensional forms, as well as multimedia art works, that communicate feelings, ideas, and understandings, using elements, principles, and techniques of visual arts as well as current media technologies

Language: Oral Communication

  1. Listen in order to understand and respond appropriately in a variety of situations for a variety of purposes;
  2. Use speaking skills and strategies appropriately to communicate with different audiences for a variety of purposes

Language: Reading

Read and demonstrate an understanding of a variety of literary, graphic, and informational texts, using a range of strategies to construct meaning

Language: Writing

  1. Generate, gather, and organize ideas and information to write for an intended purpose and audience;
  2. Draft and revise their writing, using a variety of informational, literary, and graphic forms and stylistic elements appropriate for the purpose and audience


Concepts in financial literacy from the Financial Literacy (2010) document and environmental literacy from the Acting Today Shaping Tomorrow (2009) documents are met throughout this activity.


Sharklet™ Technologies Inc.(2010). Sharklet™ Surface Protection. Retrieved from:

Sustainably Minded Interactive Technology (2013). Retrieved from:


Allison Dow was a pre-service teacher at Brock University when she wrote this article. Allison was a recipient of the 2013 Don Galbraith Pre-Service Teacher Award of Excellence with this submission.

Interactive Science Notebooks – Building Paper Bridges Grade 5

bridge from 123rf

By Lisa Ng.


As the need arises for educators to teach beyond the surface of the iceberg, a new era of documentation between the teacher and students have emerged – the Interactive Science notebook. Interactive notebooks are about more than gluing sheets on paper, they are about creating opportunities where each student can show their own voice and express their own ideas.  And realize that what they say MATTERS.
Click on the link below for a full 3-part INB lesson on building paper bridges in the classroom (Grade 5 – Forces acting on Structures and Mechanisms)

Link to document