Idea 17of 22Builds onMillilitres and litres
Big unit to small unit: multiply
When you change to a smaller unit, do you multiply or divide?
Today you'll discover
- why the number must grow
- what to multiply by
- how to check the answer
Think firstA board 3 m long
To write the board's length in centimetres, what do you do?
Decide first, then press Next. Watch each big piece break into small ones.
A board drawn as a long bar, 3 m. Under it, three tiles of 1 m; then each metre cut into strips and marked 100 cm, 300 cm in all. The working reads 3 m = 300 cm, 3 × 100 = 300. The last step shows a 4 kg bag of rice drawn as a bar.
See the whole ideathe big idea and the key word, in one place
The big idea
Big unit to small unit: multiply, because each big unit holds many small ones.
What to multiply by
How many small units fit in one big one.
- cm to mm× 10
- m to cm× 100
- km to m× 1000
- kg to g× 1000
- L to mL× 1000
Easy to get wrongCheck: going to a smaller unit, the number must get bigger.
Key word
- converting down
- writing an amount in a smaller unit; you multiply
Ready to use it?
- Convert a bigger unit into a smaller one.