Science · Kindergarten · The Senses and Scientific Inquiry · Weeks 28-36

Materials for Building

Students investigate which materials are best suited for different purposes based on their properties.

• Common Core State Standards
• K-ETS1-1

About This Topic

Materials selection is the heart of practical engineering, and this topic gives Kindergarteners a chance to think like builders. Aligned with K-ETS1-1, students investigate which materials are best suited for specific purposes based on their observable properties. A bridge needs rigid, strong materials; a blanket needs flexible, soft ones; an umbrella needs waterproof ones. The goal is to connect a material's properties to its function.

In the US K-12 engineering framework, this topic introduces the idea that design decisions are based on criteria , the requirements a solution must meet , and constraints , the limits on what materials or methods are available. Even at Kindergarten, students can grapple with questions like 'Why can't we make a blanket out of wood?' and give property-based answers.

Active learning is productive here because the connections become obvious when students test materials rather than just discuss them. Placing a piece of aluminum foil, a paper towel, a plastic bag, and a cloth over a cup of water and squirting water on each immediately reveals which is waterproof. Hands-on testing turns a vocabulary lesson into an evidence-based argument.

Key Questions

1. Justify what makes a material good for building a bridge versus a blanket.
2. Design a structure using only flexible materials.
3. Evaluate which material would be best to make a waterproof umbrella.

Learning Objectives

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

Before You Start

Exploring the Five Senses

Why: Students need to be able to use their senses, especially touch and sight, to observe and describe material properties.

Basic Observation Skills

Why: Students must be able to notice and describe differences between objects to compare materials.

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.

Watch Out for These Misconceptions

Common Misconception

The best material is always the strongest one.

What to Teach Instead

Strength is appropriate for some purposes (bridges, containers) but not others (blankets, bandages, pillows). Matching materials to purpose means choosing the right property for the job, not the most impressive property in general. Design challenge testing makes this concrete.

Common Misconception

Natural materials like wood and cotton are always better than synthetic ones like plastic.

What to Teach Instead

Each material has properties suited to specific purposes. Plastic is better for waterproofing; cotton is better for breathable warmth. The question is always which material's properties match the design criteria.

Common Misconception

If a design doesn't work, the materials were wrong.

What to Teach Instead

Design failures can come from the structure, the assembly, or the material choice. Testing the same material in multiple configurations helps students isolate which factor caused the problem , an important engineering habit of mind.

Active Learning Ideas

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.

30 min·Pairs

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.

20 min·Small Groups

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.

15 min·Pairs

Real-World Connections

• Construction workers choose specific materials like steel beams for skyscrapers because they are strong and rigid, while using flexible materials like tarps for temporary coverings.
• Toy designers select materials for different toys based on safety and function. For example, soft, flexible plastics are used for baby toys, while hard, rigid plastics are used for building blocks.

Assessment Ideas

Exit Ticket

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

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

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.

Frequently Asked Questions

How do I scaffold materials-selection thinking for Kindergarteners?

Start with clear contrasts: show a rigid material and a flexible one, then ask which would make a better hinge. Build from obvious cases to less obvious ones. Using the sentence frame 'This material would work for this because it is...' gives students a structure for connecting property to function.

What does K-ETS1-1 expect in terms of materials and design?

K-ETS1-1 asks students to define a simple design problem and consider solutions that include the properties of materials needed. At Kindergarten, this means students can say why a specific material fits or doesn't fit a design goal, using observable properties as evidence rather than just preference.

How does active learning support materials investigation?

Testing materials hands-on produces evidence that is personal and memorable. When a student's paper bridge collapses but their popsicle-stick bridge holds the toy animals, they have a direct experience of why rigidity matters for a bridge. That experience is more persuasive than any explanation.

What safety considerations apply to Kindergarten materials testing activities?

Avoid sharp edges on cardboard and wire. Check that no materials have been treated with chemicals (some craft sticks and foam pieces have coatings). Use only food-safe liquids for waterproofing tests. Small material pieces can be a choking hazard , supervise closely and collect all pieces after the activity.