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Numbers, units and arithmetic

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# 2.4 Measuring length

The basic SI unit for length is the metre, abbreviation m.

The animation below illustrates how to convert between the most commonly used units of length, kilometres (km); metres (m); centimetres (cm); millimetres (mm) and micrometres (μm).

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For example, to convert 6.23 km into cm, multiply by 1000 to convert into m, and then mulitply by 100 to convert the measurement into cm.

So 6.23 km = 6.23 × 1000 m = 6230 m = 6230 × 100 cm = 623 000 cm.

Try some yourself – use the calculator to type in the amount and then choose the units you want to convert. Then choose the operation (multiply or divide) and the factor. Then select check to see if your answer is correct.

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