ScienceGrade 3

Which Material Builds the Strongest Tower?

Strength means how much weight a material can hold before it buckles or

Learning Objective

Students will learn that a material's **strength** depends on its properties — and that SHAPE changes strength too (flat paper is weak, folded/rolled paper is strong) — by running a fair test: same-size pieces of paper, foil, and cardboard, stacking books on each mini-tower until it buckles. (TEKS 3.6D — choose materials by properties to solve problems; NGSS 3-5-ETS1-2 test solutions.)

What You'll Learn

The same material is stronger in a different SHAPE — flat paper crumples, but
Cardboard is stiff and thick — it holds more weight than paper or foil of the
A fair test: same size pieces, same stack of books, add weight until each
Engineers pick materials by testing properties — strongest isn't always

Words to Know

Strength: How much weight a material can hold before it breaks or buckles.; The cardboard showed the most strength.
Stiff / rigid: Doesn't bend or fold easily.; Cardboard is stiff; paper is floppy.
Buckle: When a tower folds or collapses under weight.; The paper tower buckled at four books.
Cylinder: A tube shape — rolled paper becomes a strong column.; The paper rolled into a cylinder held ten books.
Fair test: Changing only one thing — the material — so the result means something.; Same-size pieces, same books, one at a time.

Check What You Learned

Quick Quiz

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What does strength measure?

Fun Facts

Strength is how much load a material bears before it buckles or tears — a testable physical property
Source: TEKS 3.6D material properties; standard engineering definition
Shape changes strength — the same flat sheet of paper that crumples under one book holds a stack when rolled into a cylinder or folded into a column; curved/folded walls distribute load
Source: classic paper-column classroom demo; structural engineering basics
Cardboard is stiff/rigid and bears more weight than paper or foil of the same size — stiffness resists buckling
Source: material property comparison; corrugated cardboard design
Corrugated cardboard itself proves the shape trick — a wavy inner layer sandwiched flat makes light material strong
Source: cardboard construction; packaging engineering
Eggshells and arches are strong because curved shapes spread force — the same principle as rolled paper
Source: structural form examples in elementary engineering texts
A fair test keeps size, books, and stacking order identical — only material changes
Source: NGSS 3-5-ETS1-2/3 controlled comparison

Lesson Info

Grade 3

2026-10-31

Standards Alignment

TEKS 3.6D
demonstrate that materials can be combined/selected based on physical properties to create or modify objects/solutions
3-5-ETS1-2
generate and compare multiple possible solutions based on how well each meets criteria and constraints
3-5-ETS1-3
plan and carry out fair tests in which variables are controlled