Explanation

The metre (m) is a unit of length in the International System of Units (SI) and is the base unit of length. The millimetre (mm) is a subunit of the metre, which is equal to 1/1000th of a metre.

To convert a length measured in metres to millimetres, you can use the following conversion factor:

1 m = 1,000 mm

This means that one metre is equal to 1,000 millimetres. So to convert one metre to millimetres, you can multiply 1 by 1,000:

1 m = 1 x 1,000 = 1,000 mm

Therefore one metre is equal to one thousand millimetres. This conversion factor is widely used in many fields, such as engineering, construction and manufacturing.