Science Fenns K-5Grades K to 5
A child at a workbench building a small boat from foil, craft sticks and a sponge, testing it in a tub.

Science / All lessons / Stuff and What It Is Like

Build with the Right Stuff

Pick materials for their properties. Say why.

Lesson 13 of 41

Try this first

Before we start

Today’s story

Build with the Right Stuff

Sam wants to build a boat that holds ten pennies. He has foil, paper, a sponge and a craft stick. He tries paper first. It gets soggy and sinks.

He folds foil into a boat shape. It floats and holds six pennies. He changes the shape and tries again. Now it holds nine.

Builders choose materials by their properties. They test and improve. The steps show how.

See it

Five steps. Every time.

    Hands on

    Float a boat

    30 minutes · Do this with a grown-up nearby

    You need

    • Foil
    • Paper
    • Craft sticks
    • A sponge
    • A tub of water
    • Pennies
    • Tape
    • Paper and pencil

    Do this

    1. Say your goal. Hold the most pennies.
    2. Predict which material works best.
    3. Build a boat from one material.
    4. Float it in the tub.
    5. Add pennies one at a time.
    6. Count how many it holds.
    7. Change the shape and try again.
    Write or draw: A table with material, shape and pennies held, plus a sentence about your best design.

    Watch for: Notice flat bottoms hold more than pointy ones.

    Safety: Wipe spills right away. Never put anything in your mouth.

    Same every time

    Three rules

    Rule 1Match properties to the job.

    Strong things hold weight. Waterproof things keep water out.

    Rule 2Give a reason for your choice.

    That is how you show your thinking.

    Rule 3Test and improve.

    Few designs work the first time.

    Grandpa Fenn’s notebook

    Say it like a scientist

    property
    Something that describes a material, like strong or waterproof.
    design
    A plan for how to build something.
    criteria
    What a design must do to be a good one.

    Poppy’s quiz

    Six questions

    Tap an answer. Green means right. You will see why.

    Talk about it

    Say it out loud

    • Which material was best for your boat? How do you know?
    • What things at home are made from a good material for their job?
    Did you know

    Some bridges use steel because it is strong and can be shaped, while some roofs use wood or tile.

    Someone who does this

    A welder joins metal pieces for buildings, trucks and bridges.

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