Last week you learned about properties. This week we look closer at four important ones: hard, soft, rough, and smooth.
Hard and soft tell us what happens when we press on a material. A hard material does not squish. Press on a rock. It stays the same! A soft material squishes or changes shape. Press on a marshmallow. It squashes down.
Rough and smooth tell us about the surface of a material. The surface is the outside part we touch. A rough surface has bumps you can feel. A smooth surface feels flat and even.
Here is a tricky idea: a material can be hard AND smooth, like glass. It can be soft AND rough, like a scratchy wool sweater. Today you will explore surfaces like a scientist!
1. What happens when you press on a soft material?
2. What do we call the outside part of a material we touch?
3. Name something that is hard and smooth.
4. Can a material be soft and rough at the same time? Give an example.
Write what each word means in your own words.
For each object, circle one word from each pair.
| Object | Hard or Soft? | Rough or Smooth? |
|---|---|---|
| A glass marble | HARD / SOFT | ROUGH / SMOOTH |
| Tree bark | HARD / SOFT | ROUGH / SMOOTH |
| A cotton ball | HARD / SOFT | ROUGH / SMOOTH |
| Sandpaper | HARD / SOFT | ROUGH / SMOOTH |
| A silk ribbon | HARD / SOFT | ROUGH / SMOOTH |
| A brick | HARD / SOFT | ROUGH / SMOOTH |
Write T for true or F for false in each circle.
Draw something hard, something soft, and something rough.
1. Why do playgrounds have soft ground under the swings?
1. A rock is ______________ because it does not squish.
2. A pillow is ______________ because it changes shape.
3. Sandpaper feels ______________ because it has tiny bumps.
4. A mirror feels ______________ and flat.
5. The outside part of a material is its ______________ .
6. To test hardness, we ______________ on the material.
You need: a bag and a grown-up to put 4 objects inside.
Do not peek! Feel each object inside the bag. Circle the properties. Then guess what it is.
| Object | Circle what you feel | My guess |
|---|---|---|
| 1 | HARD / SOFT ROUGH / SMOOTH | |
| 2 | HARD / SOFT ROUGH / SMOOTH | |
| 3 | HARD / SOFT ROUGH / SMOOTH | |
| 4 | HARD / SOFT ROUGH / SMOOTH |
How many did you guess right? __________ out of 4
You will make texture rubbings with paper and crayons! Find some bumpy surfaces around your home.
| I learned... | Circle one |
|---|---|
| The difference between hard and soft | YES / NOT YET |
| The difference between rough and smooth | YES / NOT YET |
| A material can have two properties | YES / NOT YET |