- Define and explain Choosing Materials in your own words
- Use key terms such as material accurately
- Apply what you have learned to new examples and questions
- Avoid the common mistakes learners make with this topic
This lesson focuses on Choosing Materials: decide which material suits a job, like glass for windows or fabric for clothes.
Decide which material suits a job, like glass for windows or fabric for clothes.
Key ideas
Matching materials to jobs
People choose materials for their properties: windows are made of glass because it is transparent, and wellington boots are made of rubber because it is waterproof and bendy. A material that is perfect for one job can be wrong for another — glass windows let in light, but glass would be a poor choice for a football. Good designers always ask what the object needs to do first.
Sorting by one property
When you sort materials, pick just one property at a time, for example magnetic or not magnetic. A fridge magnet sticks to steel but not to plastic, wood or glass, so steel goes in one group and the others go in another. Using one rule keeps the groups fair and makes the pattern easy to see.
Key term — material: Anything things are made from, such as wood, plastic, glass, fabric or metal.
Which material would be best for a window: wood, glass or fabric? Give a reason.
Glass, because it is transparent so light can pass through and you can see through it.
Answer: Glass, because it is transparent so light can pass through and you can see through it.
- Saying a material is useless because it failed one test Failing one test does not make a material useless. Fabric soaks up water, which is bad for a raincoat but perfect for a towel — the job decides which properties matter.
- Sorting by colour alone Colour is a poor sorting rule because many different materials can be the same colour. Sort by a property that tells you something useful, like hardness or waterproofness.
Practice
Plastic is a good choice because it is smooth, so children slide easily, and waterproof, so rain does not damage it. Other sensible answers with two properties are acceptable.
It is waterproof, so rain cannot soak through it.
Any two sensible properties, for example whether they are magnetic and whether they are waterproof (metal versus wood).
False. Iron and steel are magnetic, but metals such as copper and aluminium are not.
Quick check
Which of these best defines "material"?
You sort buttons into shiny and dull. Why is this a fair sorting rule?
- Choosing Materials: decide which material suits a job, like glass for windows or fabric for clothes.
- Matching materials to jobs: People choose materials for their properties: windows are made of glass because it is transparent, and wellington boots are made of rubber because it is waterproof and bendy.
- property: Something you can observe about a material, for example whether it is hard, shiny, rough or stretchy.
- Watch out for: saying a material is useless because it failed one test