Kilometres, capacity and the mass of water
Convert metres and kilometres, tell a container's capacity from the volume of liquid in it, and see that one litre of water is 1000 cubic centimetres and weighs 1 kg.
- France: grade 2
- Germany: grade 3
- Iran: grade 5
Guide
For long distances we use the kilometre: 1 kilometre = 1000 metres. Going from a bigger unit to a smaller one we multiply, and the other way we divide: 2 km 300 m is 2000 + 300 = 2300 m.
The capacity of a container is the most liquid it can hold; a bottle's capacity is 1 litre, for example. The volume of the liquid in it is how much is in it right now, which can be less than the capacity.
To count, measure the capacity with a smaller container: if a teapot holds 1200 ml and each glass holds 150 ml, the teapot holds 8 glasses of tea.
A cube with 1 cm edges holds 1 ml of water. A cube with 10 cm edges is 1000 cubic centimetres, so 1000 ml or 1 litre.
1 ml of water has a mass of 1 g. So 1 litre of water has a mass of 1000 g, which is 1 kg.