Teaching mathematics

1.3 The metric system

The metric system is based on grams (g), litres (l) and metres (m).

The prefixes always mean the same. The common prefixes are as follows.

Kilo 1000

  • 1 kg = 1000 g
  • 1 km = 1000 m

Centi 1/100

  • 1 cm = 1/100 metre
  • 100 cm = 1 metre

Milli 1/1000

  • 1 mm = 1/1000 m
  • 1000 mm = 1 m
  • 1 millilitre = 1/1000 litre
  • 1000 ml = 1 litre

Water connects all three measures!

  • 1 cm × 1 cm × 1 cm = 1 cubic centimetre (cm3) and it holds 1 ml of water which weighs 1 gram (g).
  • 10 cm × 10 cm × 10 cm = 1000 cubic centimetres and it holds 1 litre of water weighing 1 kg.

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