Science · Grade 1 · Materials, Objects, and Structures · Term 2

Testing Material Strength

Students will conduct simple tests to determine which materials are strong, weak, bendable, or rigid using various objects and tools.

• Ontario Curriculum Expectations
• 2-PS1-2

About This Topic

Stable Structures introduces the basic principles of engineering and design. Students explore what makes a structure stay upright and support weight, focusing on the importance of a wide base and the strength of different shapes. In Ontario, this unit encourages students to look at the world around them, from the CN Tower to local bridges and traditional Indigenous dwellings like the wigwam or longhouse, to see how humans have solved the problem of stability over time.

Students learn through trial and error, discovering that the way materials are joined and the shapes used (like triangles) significantly impact a structure's performance. This topic is inherently hands-on and benefits from a 'maker' mindset. This topic comes alive when students can physically build and test their own designs in a collaborative environment.

Key Questions

1. Explain why some materials break easily while others do not.
2. Design a test to compare the strength of paper versus cardboard.
3. Evaluate which material would be best for building a strong bridge.

Learning Objectives

• Classify materials as strong, weak, bendable, or rigid based on observational data from testing.
• Compare the strength of two different materials, such as paper and cardboard, by designing and conducting a simple test.
• Explain why certain materials are more suitable than others for building structures that need to withstand force.
• Identify the properties of materials that make them suitable for specific purposes, like building a bridge.

Before You Start

Properties of Objects

Why: Students need to be able to identify and describe basic observable properties of objects, such as color, size, and texture, before they can classify materials by strength or flexibility.

Cause and Effect

Why: Understanding that actions have consequences is foundational for grasping how applying force to a material leads to a specific outcome like bending or breaking.

Key Vocabulary

Strong	A material that can resist bending, breaking, or deforming when a force is applied to it.
Weak	A material that breaks or bends easily when a force is applied to it.
Bendable	A material that can be shaped or curved without breaking.
Rigid	A material that is stiff and does not bend or change shape easily.

Watch Out for These Misconceptions

Common Misconception

Taller structures are always less stable.

What to Teach Instead

Students often think height is the only factor in falling. By experimenting with weighted bases, students can see that a tall structure with a heavy, wide bottom can be more stable than a short, top-heavy one.

Common Misconception

Heavy materials always make a structure stronger.

What to Teach Instead

Students may think a heavy block is better than a light one. Through hands-on testing, they can discover that how materials are connected (the joints) is often more important than the weight of the material itself.

Active Learning Ideas

Simulation Game: The Great Base Challenge

Groups are given blocks and challenged to build the tallest tower possible. They then repeat the task but must make the base twice as wide, comparing which tower is harder to knock over.

35 min·Small Groups

Gallery Walk: Shape Hunt

Students walk around the school or look at photos of famous structures. They use 'viewfinders' (paper frames) to spot and draw triangles, squares, and arches, then share why they think those shapes were used.

30 min·Pairs

Inquiry Circle: The Paper Bridge

Pairs try to build a bridge between two books using only one sheet of paper. They experiment with folding the paper (corrugation) to see how changing the shape makes the structure more stable and able to hold weight.

40 min·Pairs

Real-World Connections

• Bridge engineers select specific materials, like steel or reinforced concrete, based on their strength and rigidity to ensure bridges can safely support heavy traffic and withstand weather conditions.
• Toy designers choose materials for toys based on their properties. For example, a flexible plastic might be used for a bouncy ball, while a rigid plastic is used for building blocks that need to hold their shape.

Assessment Ideas

Exit Ticket

Give each student a small object made of a common material (e.g., a pencil, a paper clip, a rubber band). Ask them to write down if the material is strong, weak, bendable, or rigid, and to briefly explain why based on their experience.

Quick Check

Present students with three different objects (e.g., a straw, a wooden ruler, a piece of fabric). Ask them to hold each object and try to bend it. Then, ask: 'Which object is the most rigid? Which is the most bendable? Why?'

Discussion Prompt

Pose the question: 'Imagine you are building a small house for a toy animal. Which material would you use for the walls, and why? Which material would you use for the roof, and why?' Listen for students to connect material properties to function.

Frequently Asked Questions

How can active learning help students understand stable structures?

Active learning allows for 'productive failure.' When a student's tower falls, they aren't just getting an answer wrong; they are receiving immediate physical feedback. This encourages them to analyze the cause (e.g., 'the base was too narrow') and iterate on their design, which is the heart of the engineering process.

What are some examples of Indigenous structures I can teach?

Discuss the Haudenosaunee Longhouse, which used arched saplings for strength, or the Anishinaabe Wigwam. Explain how these structures were designed to be stable using local natural materials and how their shapes helped them withstand Ontario's wind and snow.

What are the best materials for Grade 1 building activities?

Use a variety of 'low-stakes' materials: wooden blocks, plastic interlocking bricks, cardboard scraps, straws, and masking tape. Recycled materials like cereal boxes and yogurt containers are also excellent for encouraging creativity without fear of wasting supplies.

How do I assess 'stability' in a Grade 1 classroom?

Use simple, consistent tests. A 'wobble test' (shaking the table slightly) or a 'load test' (placing a standard weight like a beanbag on top) provides clear, observable evidence for students to evaluate their own work.