Curious Investigators: Exploring Our World · 3rd Class · Materials and Change · Autumn Term

Choosing the Right Material

Students will apply their knowledge of material properties to select appropriate materials for specific purposes.

• NCCA Curriculum Specifications
• NCCA: Primary - Materials

About This Topic

Choosing the Right Material guides students to match properties like strength, flexibility, waterproofing, and absorbency to specific tasks. For example, they select wood for a bridge model because it resists bending, or plastic for a waterproof pouch since it repels water. This topic builds directly on NCCA Primary Science standards for materials, where students observe and test everyday items to justify selections.

Within the Materials and Change unit, students evaluate how properties determine suitability, such as glass for transparency in a lantern or fabric for flexibility in clothing. They design simple products, like a boat or tool, explaining choices with evidence from tests. This develops critical skills in justification, evaluation, and application, linking properties to real-world functions and change over time.

Active learning excels for this topic because students conduct hands-on tests and iterative designs. Sorting materials by properties, building prototypes, and peer-reviewing choices make abstract concepts concrete. Collaborative challenges reveal trade-offs, like strength versus weight, helping students internalize decision-making processes through trial and reflection.

Key Questions

1. Justify the selection of a particular material for a given task.
2. Evaluate how material properties influence its suitability for different uses.
3. Design a product using materials with specific desired properties.

Learning Objectives

• Justify the selection of a specific material for a given task, citing at least two relevant properties.
• Evaluate how a material's properties, such as flexibility or absorbency, influence its suitability for different uses.
• Design a simple product, like a rain hat or a tool, using materials with specific desired properties and explaining the choice of each material.
• Compare and contrast the suitability of two different materials for the same task based on their properties.

Before You Start

Observing and Describing Materials

Why: Students need to be able to identify and describe basic material properties before they can evaluate their suitability for tasks.

Testing Material Properties

Why: Students must have experience conducting simple tests for properties like strength or absorbency to use that data for justification.

Key Vocabulary

property	A characteristic of a material, such as hardness, flexibility, or absorbency, that can be observed or measured.
suitability	How well a material is fitted or appropriate for a particular job or purpose based on its properties.
absorbency	The ability of a material to soak up liquids, like a sponge soaking up water.
waterproof	A material that does not allow water to pass through it.
flexibility	The ability of a material to bend easily without breaking.

Watch Out for These Misconceptions

Common Misconception

Shiny materials are always the strongest.

What to Teach Instead

Students often judge by appearance alone. Hands-on strength tests with weights show matte cardboard holds more than shiny foil. Peer comparisons during group trials correct this by emphasizing evidence over looks.

Common Misconception

Any waterproof material works for everything.

What to Teach Instead

Waterproofing alone ignores other needs like strength. Boat-building activities reveal plastic film floats poorly under weight. Iterative testing helps students balance multiple properties through redesign discussions.

Common Misconception

The heaviest material is best for all tasks.

What to Teach Instead

Weight confuses strength perceptions. Relay tests compare light sponge versus heavy wood for flexibility. Collaborative data sharing clarifies context-specific choices.

Active Learning Ideas

Sorting Stations: Property Match-Up

Prepare stations with materials like paper, foil, cloth, and wood. Students test properties such as bendiness, waterproofing, and strength using simple tools like droppers and weights. Groups sort materials into charts for tasks like 'best for rain protection' and justify picks.

35 min·Small Groups

Design Challenge: Build a Boat

Provide trays of materials including straws, clay, foil, and fabric. Students design and test boats for flotation and waterproofing in water trays. They revise based on results and present property justifications to the class.

45 min·Pairs

Material Testing Relay

Set up a relay course with tests: drop for strength, pour water for absorbency, bend for flexibility. Teams test one material per leg, record data on clipboards, then vote on best for a playground tool.

30 min·Small Groups

Product Gallery Walk

Students create posters showing a designed product, listed properties, and tests. Class walks the gallery, asking questions and voting on most suitable designs. Discuss group insights.

40 min·Whole Class

Real-World Connections

• Construction workers choose specific types of wood, concrete, or steel for building bridges based on their strength and ability to withstand weather, ensuring the bridge is safe and durable.
• Shoe designers select different materials like leather, rubber, and mesh for various parts of a shoe. Leather provides durability, rubber offers grip for the sole, and mesh allows for breathability.

Assessment Ideas

Exit Ticket

Give each student a picture of an object (e.g., a raincoat, a hammer handle, a sieve). Ask them to write down one material that would be suitable for making it and list two properties that make that material a good choice.

Quick Check

Present students with three material samples (e.g., paper, plastic wrap, fabric). Ask them to predict which would be best for wrapping a sandwich to keep it fresh and explain their reasoning based on the property of waterproofing or absorbency.

Discussion Prompt

Pose the question: 'If you were designing a new type of playground equipment, what material would you choose for the slide and why?' Encourage students to discuss properties like smoothness, durability, and temperature resistance.

Frequently Asked Questions

How do I teach students to justify material choices?

Start with familiar tasks like packing a lunch. Guide students to list required properties, test samples, and explain selections with 'because' statements. Use rubrics for evidence-based justifications. Display student work to model strong reasoning, reinforcing NCCA skills in evaluation.

What active learning strategies work best for Choosing the Right Material?

Design challenges and testing stations engage students fully. In boat builds or sorting relays, they test properties directly, revise based on failures, and discuss trade-offs in pairs. This builds deeper understanding than lectures, as physical interaction and collaboration make property-function links memorable and applicable.

How can I assess material property knowledge?

Use performance tasks like designing a product with a written justification. Observation checklists track testing skills, while peer reviews evaluate explanations. Portfolios of before-and-after designs show growth in decision-making, aligning with NCCA standards.

What everyday materials work for property tests?

Household items like foil, cloth scraps, straws, clay, paper, and wood blocks suit 3rd class. Test waterproofing with water droppers, strength with books, flexibility by bending. Rotate materials weekly to explore variety and connect to home life.