Materials for Building

Young children learn best by touching, testing, and talking about real things. When Kindergarteners handle materials, build small structures, and feel differences between soft and stiff items, they connect abstract ideas like strength and flexibility to the physical world around them.

• Kindergarten
• Science
• 3 activities
• 15 min–30 min

Learning Objectives

1. Classify materials based on observable properties such as rigidity, flexibility, and absorbency.
2. Compare the suitability of different materials for specific building purposes, like bridges or blankets.
3. Explain why a material's properties determine its function in a structure.
4. Design a simple structure using only materials with specific properties, such as flexibility.

Problem-Based Learning

⏱ 30 min·Pairs

Engineering Design Challenge: Build a Bridge for Toy Animals

Give pairs a set of mixed materials: cardboard strips, rubber bands, popsicle sticks, tissue paper, and aluminum foil. Their goal is to build a bridge that holds at least two small toy animals across a 10-centimeter gap. After building, pairs test their bridges and describe which material did the most important work and why.

Prepare & details

Justify what makes a material good for building a bridge versus a blanket.

Facilitation Tip: During the bridge challenge, hold a quick group vote before building: ‘Which material do you think will hold the most toy animals?’ so students articulate predictions.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Problem-Based Learning

⏱ 20 min·Small Groups

Testing Activity: Which Material Is Waterproof?

Set up four material samples at each table: paper towel, plastic wrap, fabric, and wax paper. Students drip a small amount of water on each and observe what happens. Groups sort materials into 'lets water through' and 'keeps water out' and use their results to decide which would make the best umbrella material.

Prepare & details

Design a structure using only flexible materials.

Facilitation Tip: Have students wear smocks or use drop cloths during the waterproof test so spills don’t slow down the investigation.

Setup: Groups at tables with access to research materials

Materials: Problem scenario document, KWL chart or inquiry framework, Resource library, Solution presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management
• Relationship Skills

Think-Pair-Share

⏱ 15 min·Pairs

Think-Pair-Share: Why Not Use That Material?

Display an image of a blanket made of metal sheets and a bridge made of yarn. Ask students to discuss with a partner what would go wrong with each. After sharing, guide the class to articulate the property mismatch: metal is too rigid and heavy for a blanket, yarn is too flexible and weak for a bridge.

Prepare & details

Evaluate which material would be best to make a waterproof umbrella.

Facilitation Tip: Use think-pair-share questions like ‘Why didn’t the blanket work as a bridge?’ to help students isolate the property that mattered.

Setup: Standard classroom seating; students turn to a neighbor

Materials: Discussion prompt (projected or printed), Optional: recording sheet for pairs

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

Teaching This Topic

Start with objects students already know, like spoons and sponges, to introduce the language of properties. Avoid overwhelming them with too many terms at once. Focus on one property per activity so they can internalize it before layering on complexity. Research shows that when children handle materials first and then name the property, their understanding sticks better than when properties are named first and then explored.

What to Expect

Success looks like students naming properties like rigid, soft, or waterproof when choosing materials for a purpose. They should explain their choices by pointing to how the material matches the task, not just by picking what feels strong or pretty.

Watch Out for These Misconceptions

Common Misconception

During the Engineering Design Challenge, watch for students who pick the strongest material without considering how the bridge must hold toy animals, not just weight.

What to Teach Instead

After the first round, ask the class to count how many animals each bridge held, then prompt, ‘What if we used a softer material? Could we arrange it differently to hold the animals?’ to show strength isn’t the only factor.

Common Misconception

During the Testing Activity: Which Material Is Waterproof?, watch for students who think all plastics are waterproof and all fabrics are not.

What to Teach Instead

Have students test the same plastic bag and fabric scrap with a dropper, then ask, ‘Is the plastic always waterproof? Is the fabric always not waterproof?’ to highlight that thickness and coating matter too.

Common Misconception

During the Think-Pair-Share: Why Not Use That Material?, watch for students who blame the material for a failed design without considering structure.

What to Teach Instead

Prompt students to rebuild the same bridge using the same material but change the shape, then ask, ‘Did the material change? What changed instead?’ to isolate the role of structure.

Assessment Ideas

Exit Ticket

After the Engineering Design Challenge, give each student a picture of a bridge and a picture of a blanket. Ask them to draw one material that would be good for each and write one word describing why that material is a good choice.

Discussion Prompt

During the Testing Activity: Which Material Is Waterproof?, present students with a cup of water and three materials: a paper towel, a plastic bag, and a piece of fabric. Ask, ‘Which of these materials would you use to make a boat that stays dry? Why? How could we test your idea?’

Quick Check

During the Think-Pair-Share: Why Not Use That Material?, hold up different objects made of various materials (e.g., a rubber band, a wooden ruler, a paper cup). Ask students to give a thumbs up if the material is flexible and a thumbs down if it is rigid. Discuss their choices.

Extensions & Scaffolding

• Challenge: Give students five new materials (e.g., aluminum foil, straws, fabric scraps) and ask them to design a container that keeps a cotton ball dry.
• Scaffolding: Provide picture cards of properties (rigid, soft, waterproof) and have students sort materials into labeled baskets before building.
• Deeper exploration: Ask students to draw a design for a house that uses three different materials, labeling each one with its property and purpose.

Key Vocabulary

Rigid	A material that is stiff and does not bend or change shape easily. Think of a wooden block.
Flexible	A material that can bend or stretch easily without breaking. Think of a piece of cloth.
Absorbent	A material that can soak up liquids. Think of a sponge.
Waterproof	A material that does not let water pass through it. Think of a raincoat.