We add kilometres (km) for long distances and use the four operations with measurements.
1 km = 1000 m. To change a bigger unit to a smaller one, multiply by the conversion number: 2 km = 2 × 1000 = 2000 m; 4 m = 400 cm.
Remember
- 1 km = 1000 m.
- Bigger → smaller unit: multiply.