For example, in the article Distances in space, it states: When the Space Shuttle goes into space, it orbits about 700 km above the surface of the Earth. The Space revealed resources deal with extremely large distances.In abbreviated form, this length is written as 1 nm. In the Nanoscience resources, it is reported that fingernails grow at about 1 nanometre per second.In abbreviated form, this amount of energy is written as 25 mJ. One unit on the UV index is roughly equivalent to 25 millijoules of UV energy falling per second on a 1 square metre area. In the You, Me and UV resources, information is given about the UV index.The first letter of the SI abbreviation represents the prefix and the second letter represents the base unit. These prefixes are decimal fractions that multiply base units for smaller measurements These prefixes multiply base units for larger measurements For small lengths, the millimetre (10 -3 m) may be the appropriate quantity, whereas for large distances, the kilometre (10 3 m) may be more appropriate. For example, the base unit of length is the metre. Larger and smaller quantities are expressed by using appropriate prefixes with the base unit.

they eliminate the confusion of old number names вЂ“ is a billion a thousand million (USA) or a million million (Europe)?.they are unique, unambiguous letter symbols.there are no long rows of zeros вЂ“ prefixes replace them.The advantages of basing the multiples and submultiples on the decimal system are:

Power of ten prefixes