Grade by Grade
Strand B: Problem Solving and Innovating · Wonder, Explore, Build and Create

Exploring Materials: Hard, Soft, Bendy and Splashy

B12.2 B12.3 B12.4About 20 minutes
Learning goals
  • I can name some materials, like wood, metal, plastic, paper and cloth.
  • I can describe materials with words like hard, soft, bendy, rough and smooth.
  • I can predict and test if something will sink or float.
  • I can choose a good material for a job and tell why.

Words to know

material
What something is made of, like wood, metal, plastic, paper, cloth, glass or rubber.
sink
To go down to the bottom of the water.
float
To stay up on top of the water.
bendy
Easy to bend without breaking, like a pipe cleaner or paper.
waterproof
Does not let water through, like a raincoat or rubber boots.

What is it made of?

(Grown-up: read aloud.)

Tap on the table. Is it hard or soft? Squeeze your sweater. Is it hard or soft?

Everything around us is made of something. What something is made of is called its material.

MaterialThings made of it
wood 🪵a table, a pencil, a block
metal 🔩a spoon, a key, a pot
plastic 🧴a toy, a bottle, a cup
paper 📄a book, a box, a paper bag
cloth 👕a shirt, a blanket, a mitten
rubber 🥾boots, an eraser, a balloon
glass 🪟a window, a jar
Point to something in your home made of each material.

Words to describe materials

Scientists use special words to tell about materials. Let's touch and say:

  • hard 🪨 or soft 🧸
  • rough (bumpy, like a carrot peel or tree bark) or smooth (like a window)
  • bendy (like paper) or stiff (like a block)
  • stretchy (like an elastic band)
  • heavy or light (a light thing is easy to lift)
  • see-through (like window glass)
A smooth stone, a soft knitted mitten, a piece of rough tree bark, an elastic band, a glass jar and a sheet of paper on a table.
Which one is soft? Which one is rough? Which one is stretchy? Which one is see-through? AI-generated image
bendy | stiffstretchysee-through | notpaperblockpullelastic bandglass jar?box
Paper is bendy but a block is stiff. An elastic band is stretchy. You can see the marbles in a glass jar because glass is see-through, but not inside a box.
Worked example

Let's test: sink or float?

We have a tub of water and these things: 🍎 an apple, 🪨 a small rock, 🔑 a metal key, 🦆 a plastic bath duck, 🥄 a metal spoon, 🍂 a dry leaf.

  1. I guess. Before we drop anything in, we predict. Point to each one and say "sink" or "float."
  2. I try and look. Gently put each thing in the water, one at a time. Watch: does it go down to the bottom, or stay on top?
  3. I sort. Put the floaters on one towel and the sinkers on another towel.
  4. I tell. "The apple, the duck and the leaf floated. The rock, the key and the spoon sank."

Float: 🍎 🦆 🍂 Sink: 🪨 🔑 🥄

floatsinkappleduckleafrockkeyspoon
What happened in our test: the apple, duck and leaf floated on top. The rock, key and spoon sank to the bottom.
ThingMy guessWhat happened
🍎 apple?floats
🪨 rock?sinks
🔑 key?sinks
🦆 bath duck?floats
🥄 metal spoon?sinks
🍂 leaf?floats
A recording chart. Your child can fill in "My guess" with a ✓ for float or an ✗ for sink.

Surprises are good

Were you surprised? Many people guess that a big apple will sink, but it floats! A surprise is not a mistake. It means you learned something new.

The right material for the job

We pick materials because of what they are like.

  • A raincoat is made of plastic or rubber because it is waterproof. A paper raincoat would get soggy! ☔
  • A window is made of glass because it is see-through.
  • Mittens are made of soft, warm cloth (like wool or fleece) so our hands stay warm. 🧤
Hands-on activity

Sink or float tub

You need: a sink, tub or big bowl of water, a towel, and 6 small things from home that can get wet (for example: a plastic lid, a crayon box (closed), a metal spoon, a sponge, a stone, a plastic toy).

  1. Lay the 6 things on the towel.
  2. Pick up each thing and predict: sink or float? Your grown-up makes a ✓ or ✗ on paper.
  3. Test each one. Watch closely.
  4. Sort them into a sink pile and a float pile.
  5. Count: how many floated? How many sank?

Talk about it: "Which one surprised you? What do the floaters have in common?"

Grown-up: stay right beside your child near water at all times.

Just for fun

Riddle: What gets wetter the more it dries?

A towel! 🧺

Your turn

1

Which one is soft: 🧸 a teddy bear or 🪨 a rock?

2

Which one is bendy: a piece of paper 📄 or a wooden block?

3

🪨 Predict: will a rock sink or float?

4

🦆 Predict: will a plastic bath duck sink or float?

5

☔ What is a good material for a raincoat: paper or plastic? Why?

6

Find something in your home that is made of metal. Show your grown-up.

More practice: warm-up

1

Is a pillow hard or soft?

2

🔑 Does a metal key sink or float?

3

What is a book made of: paper or glass?

4

Which one stretches: an elastic band or a pencil?

5

🪟 Which material can you see through: window glass or wood?

More practice: on your own

1

Touch a tree trunk or a carrot peel 🥕. Is it rough or smooth?

2

🍎 Does an apple sink or float? Was it what you guessed?

3

Why are mittens 🧤 made of soft cloth and not metal?

4

🧴 An empty plastic bottle with the lid on. Sink or float? Why do you think so?

5

Name 2 things in your kitchen made of different materials.

Challenge

1

🐷 In the story of the Three Little Pigs, which house stood up to the wolf: straw, sticks or bricks? Why?

2

You want to carry water to the garden. Which is better: a paper bag or a plastic pail? Why?

3

A ball of play dough sinks. 🟢 Can you change its shape so it floats? Try it, or guess.

Check your understanding

Quiz

1.

Which one will sink?

2.

Which one is soft?

3.

What is the best material for a raincoat?

4.

Which one is stretchy?

5.

Before we test if something sinks or floats, we...

For parents and teachers

What this lesson is about. Children choose and use materials to carry out their own explorations, make predictions and observations, and talk about results using new describing words (hard, soft, rough, smooth, bendy, waterproof).

How to help at home:

  • Bath time, cooking and tidying are perfect material-talk times: "Is this spoon metal or plastic? How do you know?"
  • Always ask for a prediction before testing. Write it down so you can check it together.
  • Let your child choose what to test. Their own ideas make the best experiments.
  • Use the new words yourself, often.

Common difficulties:

  • Children often think big things sink and small things float. Testing an apple (floats) and a small key (sinks) helps change this idea. Do not worry about explaining why things float; noticing is enough at this age.
  • Some children see a wrong prediction as failing. Celebrate surprises.
  • Safety: always stay within arm's reach of a young child near any water, even a small tub, and avoid small items that could be choking hazards.