Science · Grade 3

Active learning ideas

Designing with Materials

Active learning works because students must physically engage with materials to see how their properties affect real-world outcomes. When children hold a flimsy paper strip and feel it bend under a small load, they immediately connect the idea of flexibility to design choices in a way no textbook diagram can match. Testing designs and feeling the results builds lasting understanding of material science through firsthand experience.

• Ontario Curriculum Expectations
• 3-5-ETS1-1

• 35–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Plan-Do-Review
• 45 min · Small Groups

Engineering Challenge: Paper Bridges

Provide paper, straws, tape, and string. Groups define a problem like spanning a 20 cm gap to hold 20 pennies. They sketch plans, justify material choices by properties, build, test with weights, and improve based on failures. Share results in a class gallery walk.

Justify the selection of specific materials for a design project.

Facilitation Tip

During Paper Bridges, have students first test each material alone before combining them, so they see the effect of layering and folding.

What to look for

Provide students with a scenario, e.g., 'Design a small raft to hold a toy figure in water.' Ask them to list two materials they would use and explain why each material's property is suitable for the raft's purpose.

• Remember
• Apply
• Analyze
• Self-Management
• Decision-Making
• Self-Awareness

Activity 02

• Plan-Do-Review
• 35 min · Pairs

Design Lab: Floating Boats

Supply recyclables like foam, corks, foil, and clay. Pairs design boats to carry a cargo of 10 pennies without sinking. Test in water trays, record property observations, then redesign for better buoyancy. Discuss successes as a class.

Critique the effectiveness of a design based on the properties of its materials.

Facilitation Tip

In Floating Boats, pause after the first test to ask students to share what sank fastest and why, then challenge them to change one variable.

What to look for

After students build their designs, have them present their object to a small group. Provide a simple checklist: 'Does the design meet the purpose?' 'Are the materials appropriate?' 'What is one thing that works well?' 'What is one suggestion for improvement?'

• Remember
• Apply
• Analyze
• Self-Management
• Decision-Making
• Self-Awareness

Activity 03

• Stations Rotation
• 50 min · Small Groups

Stations Rotation: Material Towers

Set up stations with popsicle sticks, marshmallows, blocks, and straws. Small groups build 30 cm towers at each, testing stability with a fan or shake table. Rotate stations, compare properties, and vote on strongest design per material set.

Construct a solution to a problem using appropriate materials and tools.

Facilitation Tip

In Material Towers, set a timer for 5-minute rotations so students rotate with their partially built towers to see others’ approaches.

What to look for

During the building phase, circulate and ask students questions like, 'Why did you choose this material for this part of your design?' or 'What property of this material makes it a good choice for holding weight?'

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 04

• Plan-Do-Review
• 40 min · Individual

Whole Class: Shelter Build-Off

Pose a problem: build a shelter for a toy figure against dripping water. Class brainstorms criteria, then individuals select materials and construct. Test with spray bottles, critique in pairs, and revise before final showcase.

Justify the selection of specific materials for a design project.

Facilitation Tip

During the Shelter Build-Off, assign roles like designer, builder, and tester so students practice teamwork and clear communication.

What to look for

Provide students with a scenario, e.g., 'Design a small raft to hold a toy figure in water.' Ask them to list two materials they would use and explain why each material's property is suitable for the raft's purpose.

• Remember
• Apply
• Analyze
• Self-Management
• Decision-Making
• Self-Awareness

A few notes on teaching this unit

Teach this topic by framing material selection as a puzzle where properties are clues to solving it. Avoid telling students which material to pick; instead, guide them to ask, 'What does this job require?' and 'What does this material bring?' Research shows that when students struggle to explain their choices, asking them to name the property and demonstrate its effect often clarifies their thinking. Remember that the goal is not perfect structures but improved reasoning through iteration.

By the end of these activities, students will confidently select materials based on specific properties and explain their choices with evidence from testing. They will use the engineering process to improve designs, articulate trade-offs between options, and respect that initial attempts often require refinement. Success looks like students listening to peer feedback and using it to revise their next build.

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Watch Out for These Misconceptions

• During Paper Bridges, watch for students who choose thick stacks of paper because they believe heavier stacks are always stronger.

  Ask these students to test a single sheet versus a folded sheet, then have them verbalize how folding changes strength without adding weight.

• During Floating Boats, watch for students who call any plastic waterproof without testing different types.

  Provide two plastic types (e.g., wax paper vs. plastic wrap) and have students test both. Ask them to describe how each behaves in water and link that to the boat’s performance.

• During Material Towers, watch for students who declare their first design perfect and resist changing it.

  Prompt them with, 'What happens if you add a second floor?' and require them to rebuild based on the new load before testing again.

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Methods used in this brief

• Plan-Do-Review
• Stations Rotation