A metric prefix precedes a unit of measurement and indicates a multiple or fraction of that unit. For example, kilo may be added to metre to indicate 1000 metres, i.e. there are 1000 metres in a kilometre. Likewise, milli may be added may be added to metre to form the word millimetre, i.e. one thousandth of ametre.The table below gives the names and symbols of all metric prefixes in common use, together with their multiple or fraction quantity. These are given in the form 10^n, where, for example, 103 is written as 10^3, and 10-3 is written as 10^-3. In addition, the short and long scale names are given. The short scale names are now used in most English speaking countries.Note that there are some exceptions. For example, as a consequence of binary mathematics, when discussing a computer’s memory or storage capacity a kilobyte (kB, KB, kbyte or Kbyte) is 1,024 bytes, i.e. 2^10 bytes. Likewise, most standards bodies now regard a megabyte as being 1,024,000 bytes, i.e. 1000 x 1024 bytes.