Science · Grade 3

Active learning ideas

Testing Material Strength

Active testing lets students feel forces directly, turning abstract ideas into memorable evidence. When they manipulate popsicle sticks and pennies, they build intuitive knowledge that connects shapes, materials, and real-world structures like bridges and towers.

• Ontario Curriculum Expectations
• 3-5-ETS1-2

• 30–45 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Stations Rotation
• 45 min · Small Groups

Stations Rotation: Force Testing Stations

Prepare four stations: bending (load straws or sticks), stretching (pull paper strips), compression (stack blocks on cardboard), twisting (wind string around dowels). Small groups rotate every 10 minutes, test with consistent forces like 10 pennies, record breaking points, and compare notes as a class.

Compare the strength of various materials under stress.

Facilitation Tip

During Force Testing Stations, place identical weights next to each material so students see how bending, stretching, and compression act differently on the same object.

What to look for

Provide students with three different materials (e.g., a flat piece of paper, a rolled paper tube, a straw). Ask them to predict which will hold the most pennies before bending or breaking. Record their predictions and then have them test each material, recording the actual number of pennies held.

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

Activity 02

• Plan-Do-Review
• 40 min · Pairs

Bridge Building Challenge

Provide popsicle sticks, tape, and marshmallows. Pairs design and build 20 cm bridges, predict load capacity, then test by adding pennies until collapse. Groups redesign once based on failures and share improvements.

Predict which material would be best suited for a specific construction task.

Facilitation Tip

For the Bridge Building Challenge, give teams identical craft sticks and ask them to document each design change and its effect on load capacity.

What to look for

Give students a scenario: 'You need to build a ramp for a toy car. Which material would you choose: a thin cardboard sheet or a thick cardboard sheet? Explain your choice in one sentence, mentioning strength or durability.'

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

Activity 03

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

Shape Strength Comparison

Give students paper, scissors, and tape. In small groups, they fold or roll paper into shapes like triangles, squares, cylinders, then test strength by stacking books. Record maximum loads and discuss why shapes differ.

Analyze how the shape of a material can affect its strength.

Facilitation Tip

In Shape Strength Comparison, have students trace identical shapes onto the same material before cutting to control thickness and isolate the shape variable.

What to look for

After building simple bridges, ask students: 'What happened to your bridge when you added weight? Did any bridges break? Why do you think some materials or shapes worked better than others? Share one thing you learned about material strength.'

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

Activity 04

• Plan-Do-Review
• 35 min · Pairs

Material Prediction Sort

Display materials like fabric, foil, wood splints. Individually, students predict and rank for a task like a flagpole, then test in pairs by applying wind (fan) or weight. Class compiles results for consensus.

Compare the strength of various materials under stress.

Facilitation Tip

During Material Prediction Sort, let students feel each material’s texture and weight before sorting to anchor predictions in sensory evidence.

What to look for

Provide students with three different materials (e.g., a flat piece of paper, a rolled paper tube, a straw). Ask them to predict which will hold the most pennies before bending or breaking. Record their predictions and then have them test each material, recording the actual number of pennies held.

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

A few notes on teaching this unit

Start with quick, hands-on trials so students notice forces immediately, then scaffold toward systematic data collection. Emphasize process over precision: the goal is to observe patterns and revise thinking, not produce perfect measurements. Keep groups small to ensure every student handles materials and records results.

Students will plan fair tests, collect concrete data, and explain how material properties and shapes affect strength. They will revise initial ideas using experimental results and present their findings with clear evidence.

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Watch Out for These Misconceptions

• During Material Prediction Sort, watch for students who assume thicker or heavier items always win.

  Have students test rolled paper tubes against flat cardboard sheets using identical loads, then record results on a class chart to show lightweight tubes can outperform heavy flat sheets.

• During Shape Strength Comparison, watch for students who believe a square frame is as strong as a triangle frame.

  Provide identical strips of cardboard and let students build triangles and squares. Add pennies to each frame and ask them to note which shape holds more weight before collapsing.

• During Bridge Building Challenge, watch for students who assume all papers or plastics behave the same.

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Methods used in this brief

• Stations Rotation
• Plan-Do-Review