Åk 6–9
8.2 Prefixes
The word prefix comes from latin and means one or more letters added to the beginning of a word.  In mathematics, every prefix which we use has a mathematical value and is used to express large numbers and words in an easy manner.  Here we will look through the prefixes for numbers between 0 and 1.


”Visible light has a wave length between 400 and 700 nanometers.”

The prefix “nano” is abbreviated to n and means billionth.

400 nm = 400 · 0.000 000 001 m = 0.000 000 4 m
400 nanometers = 400 billionth meters 

The prefix nano is often used in a branch of technology in the natural sciences which is called nano-technology. The reason that it is called nano-technology is that in this branch, people work with objects at the atomic level, and a normal atom has a diameter of 0.1 nm.

Here is a table for the most common prefixed between 0 and 1.

Deci, centi, and milli have been included in the international SI-system which is the international standard for measurements and prefixes since the end of the 1700’s. The other units from the table were included in the SI-system from 1960 on.