Materials Matter

Unit: Designing Structures and Solutions

Lesson 2 of 12

Duration: 30 minutes

Grade Level: 3rd Grade

Overview

Students will explore and investigate different materials commonly used in construction — paper, straws, and popsicle sticks. Through a hands-on activity, they will test these materials for strength and flexibility to understand why certain materials are chosen for building structures. This lesson encourages inquiry, critical thinking, and creativity while reinforcing foundational science skills aligned with Common Core standards.

Learning Objectives

By the end of this lesson, students will be able to:

Describe the physical properties (strength, flexibility) of different materials.
Test and compare materials based on how much weight they can hold or how much they bend.
Use data from tests to draw conclusions about which materials work best for building structures.
Communicate findings clearly through discussion and simple writing.

Relevant Common Core Standards

Next Generation Science Standards (NGSS) Connections:

3-PS2-1: Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object. (Focus on forces acting on materials.)
3-5-ETS1-2: Generate and compare multiple possible solutions to a problem based on how well they meet the criteria and constraints of the design problem.

English Language Arts (ELA) Standards (for integration and communication):

CCSS.ELA-LITERACY.W.3.2: Write informative/explanatory texts to examine a topic and convey ideas and information clearly.
CCSS.ELA-LITERACY.SL.3.1: Engage effectively in a range of collaborative discussions with diverse partners on grade 3 topics and texts.

Mathematics (Measurement & Data):

CCSS.MATH.CONTENT.3.MD.A.1: Solve problems involving measurement and estimation of intervals of time, liquid volumes, and masses of objects. (Weight/load tests.)

Materials Needed

Paper sheets (standard printer paper)
Straws (plastic or paper)
Popsicle sticks
Small weights or coins to test strength (identical, such as pennies)
Small containers (optional, for uniform weight)
Measuring tape or ruler
Worksheet for recording observations
Pencils
Table space for testing

Detailed Lesson Plan

1. Introduction & Engagement (5 minutes)

Begin with a brief discussion: "What do you think makes a building strong?"
Show examples of materials: paper, straws, popsicle sticks. Ask, "Which of these materials do you think are strong? Which are flexible? Why?"
Explain that today they will test these materials to see which ones are good for building different parts of structures.

Teacher Tip: Use relatable examples (e.g., "Imagine building a bridge—what materials might you want?").

2. Hands-on Activity: Testing Materials (15 minutes)

Setup:

Divide the class into groups of 3 (or pairs if homeschool). Each group gets paper, straws, and popsicle sticks.
Each group will design a small "bridge" or "beam" out of one material at a time. They will lay the material across two supports (e.g., textbooks or chairs at standard distances).
Test each beam by adding weights (pennies) one by one until the material breaks or bends noticeably.

Instructions:

Measure and record how many pennies each material holds before bending or breaking.
Observe how flexible each material is (does it bend a lot or a little?).
Fill out the worksheet to record: material, weight held, flexibility notes.

3. Group Discussion and Analysis (7 minutes)

Bring students back together to share findings.
Guide a discussion on:
- Which materials held the most weight?
- Which were the most flexible?
- How might builders decide which material to use based on these results?
Use questions like: "What if you need a bendable part? What if you need a strong part that doesn’t bend?"

4. Wrap-up & Reflective Writing (3 minutes)

Students write 2-3 sentences answering: "Which material would you choose for building a bridge and why?"
Encourage them to use evidence from the test to support their choice.
Optionally, allow students to draw a quick sketch of a structure using their chosen material.

Assessment

Participation in testing and discussion (observational).
Completion of worksheet with accurate recording of findings.
Reflective writing with clear reasoning based on data collected.

Extension Activities for Advanced Learners

Challenge students to combine materials (e.g., paper and straws) to build a structure that maximizes both strength and flexibility. Test it and record results.
Research various materials used in famous buildings or bridges (wood, steel, concrete). Create a mini-presentation or poster explaining how those materials’ properties make them suitable for construction.
Design and build a simple architectural model at home using recycled materials, explaining which materials were chosen and why.

Teacher Reflection Prompts

Did the materials provide clear evidence of differences in strength/flexibility?
Were students able to connect their observations to real-world building decisions?
Did the hands-on activity engage students, foster collaboration, and build critical thinking?
What adaptations might be necessary to deepen investigation or support different learning styles next time?

Notes for Homeschool Environment

The flexible group size allows for individualized pacing during hands-on activities.
Encourage extra conversations linking science to the student’s observations in nature (e.g., comparing flexible tree branches vs. stiff stems).
Use this lesson as a springboard to integrate art by having the student illustrate their favorite tested structures at home later.

This lesson plan respects student attention spans with a concise yet meaningful hands-on investigation, balances structured objectives with open-ended reflection, and integrates reading, writing, math, and science standards thoughtfully. It builds foundational science inquiry skills and inspires creative thinking about materials and design.

Teaching Instructions