Units of measure
Units of measure
- Metric units: mass (g, kg), length (mm, cm, m, km), capacity (ml, litres).
- Length: $1\ \text{m} = 100\ \text{cm}$.
- Capacity: $1\ \text{litre} = 1000\ \text{cm}^3$, so $1\ \text{m}^3 = 1000$ litres.
Practice
How many cm are there in 1 m?
1 m = 100 cm.
Practice
How many cm³ are there in 1 litre?
1 litre = 1000 cm³.
Squares and cubes need care
- Area: $1\ \text{m}^2 = 100^2 = 10\,000\ \text{cm}^2$.
- Volume: $1\ \text{m}^3 = 100^3 = 1\,000\,000\ \text{cm}^3$.
- Worked example: $3\ \text{m}^2 = 3 \times 10\,000 = 30\,000\ \text{cm}^2$.
Practice
Convert 3 m² to cm². (1 m² = 10 000 cm²)
3 × 10 000 = 30 000 cm².
You've got it
Key idea
- $1\ \text{m} = 100\ \text{cm}$, so $1\ \text{m}^2 = 10\,000\ \text{cm}^2$ and $1\ \text{m}^3 = 1\,000\,000\ \text{cm}^3$
- square the conversion for area, cube it for volume
- $1\ \text{litre} = 1000\ \text{cm}^3$