Top: Boat Sinking (Photo by armyasad via Pixabay)

Setting the Stage

Life preserver
(Photo by Tristan Schmurr via Wikimedia Commons)

To successfully participate in this Design & Build, students should be able to work with basic cutting tools (e.g., scissors), fasteners (e.g., low-temperature glue guns, tape) and materials (e.g., wooden craft sticks, straws) and be familiar with concepts of buoyancy (sink and float) and strong shapes. It is recommended that students participate in the Strong Shapes: Cylinders and/or It’s All In The Shape and/or Finding Out About Fasteners and/or Which Fastener is Best? Inquiries before doing this Design & Build challenge.


Students may have various experiences with sinking and floating. They may have tossed small rocks into a pond, played with toys in a bathtub or a sink, or watched boats of various sizes float on the water. Indeed, many will have had the experience of floating when they learned to swim.

(Photo by leoleobobeo via Pixabay)

In this Design & Build challenge, students will develop their Design & Build skills as they apply their prior knowledge to design and build a device that floats.

This design and build could begin from:

  • a picture provocation. Discuss using questions such as:
    • “Where might you find the first device? Who might use this device and for what purpose?”
    • “Where might you find the second device? Who might use this device and for what purpose?”
    • "What other devices can you think of the serve a similar purpose?"

  • a challenge to students to find objects and/or materials (e.g., plasticine) in the room that they think will float. Discuss using questions such as:
    • “Why did you choose that item/material?” (e.g., prior knowledge of its ability to float)
    • “How can we test our items to see if they will float?”
    • Cover of Iggy Peck, Architect by Andrea Beaty
      (Cover image by Let's Talk Science)

    • “Is it possible to make something float that sank during our tests? Why do you think that?”

  • reading a book such as Iggy Peck, Architect. Discuss using questions such as:
    • “What is the problem facing Iggy Peck and his class?”
    • “What skills does Iggy have that might help to solve the problem?”
    • “If you were Iggy, what solutions might you suggest for getting everyone safely off the island?”

Design Criteria:

As a class, students brainstorm criteria that their prototype device must meet. Educators may choose to add other criteria that are curriculum-specific, such as using joiners/fasteners, measuring, using specific materials, etc.

Design criteria examples:

  • Device must be created using only the materials provided.
  • Device must support a weight of XX grams.
  • Device must stay afloat for a minimum of xx minutes.

Materials and Preparation (Click to Expand)


  • Access to water
  • fasteners such as masking and/or duct tape, wood glue or a low temperature glue gun, etc.
  • cutting tools such as scissors, Easy Cutters, etc.
  • metre stick
  • container of pennies or small cubes to equal the determined mass the device must support
  • aluminum foil
  • modeling clay
  • craft/popsicle sticks (200 per team)
  • Styrofoam (trays, cups, or plates, and/or egg cartons)
  • plastic containers (recycled)
  • cardboard (recycled boxes or scraps)
  • different kinds of paper (recycled where possible)
  • straws


  • Collect an assortment of recycled and new materials that students will use to construct the prototype device. The materials list above is only a suggested list.
  • Set up material sourcing stations, organized by type of material. Alternatively, organize an assortment of materials to be provided.
  • For testing the devices, set up a classroom sink with some water (8-10 cm) or set up a testing station using a rectangular tub with water. Provide paper towels nearby to clean up any drips or spills.
  • Students who have not previously learned about forces may need to do some research prior to engaging in this Design & Build (e.g., buoyancy as a force)

What To Do

Students develop and apply Design & Build skills as they design, build and test a device that will float.

Students will follow the steps of the Design & Build process:

(Photo by Pezibear via Pixabay)

  • identify the problem to be solved/need to be met
  • brainstorm criteria that the prototype must meet
  • share their questions and ideas for a solution to the problem
  • discuss the advantages and disadvantages of each in order to select a potential solution to be tested
  • visualize what the solution might look like and make design sketches based on their visualizations
  • develop a design plan (e.g., identify the tasks or key steps involved in developing the solution, make decisions about tools and materials that will be needed, include labelled sketches)
  • build/develop the design idea based on the design plan
  • test their prototypes based on the design criteria
  • modify the prototype and retest it against the design criteria as necessary
  • reflect on their results and identify things that could be done to improve their prototypes


Observe and document, using anecdotal comments, photos and/or video recordings, student’s ability to:

  • Work Collaboratively - students work collaboratively to complete a task and evaluate their group processes throughout the Design & Build process
  • Generate Ideas - students use idea generation strategies, such as brainstorming, to identify possible solutions as well as make decisions about the pros and cons of each solution
  • Communicate - students communicate their thinking and learning in words/sketches/photos/videos, etc. as they identify problems, do research, develop design plans, and share design solutions
  • Work Safely - students demonstrate safe practices when using a variety of tools and materials while prototyping
  • Reflect - students reflect on the results of their prototype testing and suggest things that they might do differently to improve their prototypes

Co-constructing Learning

Saying, Doing, Representing

Educator Interactions:
Responding, Challenging

Students identify and refine the problem to be solved/need to be met.

  • “What are some of the possible solutions your group came up with?”
  • “What were some criteria that helped you to determine which solution you will develop?”

Students brainstorm and record criteria for the solution they have chosen.

  • “What words could we use to describe some of the features your device must have to be effective?”
  • “One criterion is the device must hold a mass of xx grams and stay afloat. How will you determine if this criterion has been met?”

Students visualize what the solution might look like and make design sketches based on their visualizations.

  • “Why is visualization an important skill for engineers and architects?”
  • “Why do engineers label all of the parts of their design sketches?”
  • “How are you going to represent each part of your device in the design sketch?”

Students develop a design plan (e.g., steps in creating a prototype, decisions about tools and materials).

  • “What tools might you need for building your device?”
  • “What conditions do you need to think about when determining the best fasteners to use?” (e.g., How will the fastener(s) hold up in water?)

Students build/develop and test the design idea based on their sketches and design plan (create the prototype).

  • “Which of the design criteria does your prototype meet? Which ones does it not yet meet? Why do you think this happened?”
  • “How will you need to adapt your plan in order to meet all the criteria?”

Students modify the prototype and retest it against the design criteria as necessary.

  • “What problems did you have when you re-tested your device?”
  • “What changes in your prototype might improve your results?”

Students reflect on the results of their testing and identify things that could be done differently in the future.

  • “What materials worked best? What materials did not work as well?”
  • “How might you rethink the fasteners you used?”
  • “What challenges did your team encounter in working collaboratively to complete the challenge?”
  • “How would it change your design if you had to add 5 grams to the load your device must support while afloat?”

Cross-Curricular Connections


  • Ask questions (e.g., “What problem are we trying to solve?”)
  • Communicate thoughts, feelings and ideas (e.g., while brainstorming solutions for the problem, in design plans that include 2-D design sketches, in an outline of key design steps/tasks and lists of required materials and equipment/tools)
  • Work collaboratively to come up with solutions (e.g., how to determine the most feasible solution to the problem)

Mathematical Thinking

  • Recognize and use 2-D and 3-D shapes (e.g., use cylinders as a base for their device)
  • Represent using pictures, diagrams, graphs, tables, numbers, words, and/or symbols (e.g., sketch their visualization of how their device might meet the established criteria; use tables to record tests and redesigns of their toy)
  • Measure and record mass (e.g., to ensure that their device will support the required mass and stay afloat)

Extending the Learning

If your students are interested in learning more, the following may provoke their curiosity:

    Cover of Abel’s Island by William Steig (Photo via Open Library)

  • Read the book Abel’s Island by William Steig. Discuss using questions such as:
    • “Although Abel is a mouse, his experiences are similar to those of Iggy Peck and his classmates. What characteristics does Abel have that are similar to those of Iggy?”
    • “When did Abel have to think like an engineer?”
    • “What skills does Abel have that helped him survive on the island?”
    • “What could Abel have learned from Iggy Peck about getting off of the island”
    • “How did Abel make connections between his previous experiences and his new situation?”

  • Some students may be interested in learning more about big ships and how they are built so that they will stay afloat. This video provides some easily-accessed information.