Unit Conversions (Metric)

The metric system is built on powers of 10. Here are the key conversion facts:

Length: $1 \text{ km} = 1000 \text{ m}$, $1 \text{ m} = 100 \text{ cm}$, $1 \text{ cm} = 10 \text{ mm}$

Mass: $1 \text{ kg} = 1000 \text{ g}$, $1 \text{ g} = 1000 \text{ mg}$

Capacity: $1 \text{ litre} = 1000 \text{ ml}$, $1 \text{ cl} = 10 \text{ ml}$

Converting to a smaller unit means more of them, so you multiply. Converting to a larger unit means fewer of them, so you divide.

The slider shows centimetres converted to millimetres. Try different values to see the conversion in action.

Watch it work

Question: Convert 3.5 km to metres.

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