Concept 2 of 6
Centimetres & Metres
Today's big idea
Small things use centimetres, big things use metres.
1 metre = 100 centimetres.
How it works
👀 What's going on?
You measure a book in cm. But a door? That needs a bigger unit.
💡 Here's the trick
Small things use centimetres (cm) and big things use metres (m). And 1 metre is 100 centimetres.
A pencil is 15 cm. A door is 2 m. Since 1 m = 100 cm, a 2 m door is 200 cm.
✍️ Try it
Which unit fits the length of a bus? → metres (m).
⚠️ Watch out
Use metres for big things, or the centimetre number gets huge.
Watch me solve one
Quanta solves it
“Watch how I think through one of these — then you try.”
THE PROBLEM
“Which unit fits a school bus, and how many cm is 1 m?”
- 1
Big or small?
A bus is big, so measure it in metres.
- 2
The metre link
1 metre is 100 centimetres.
- 3
Answer ✓
metres · 1 m = 100 cm
Now you try one — same steps, different story 👇
See it in action
⚡ Time to play!
Small things use cm, big things use m.
✏️
Measure a pencil in…
Quick check
✅ VERIFICATION
How many centimetres are in 1 metre?
⚡ Finish the activity above first to answer.
Keep going!
Up next: Estimate, Then Measure
Estimate first, then measure to be sure.