 
 
 
You can insert a unit prefix in front of a unit to indicate a power of ten.
The following table gives the available prefixes:
| Prefix | Name | (*10 ^) n | Prefix | Name | (*10 ^) n | 
| Y | yota | 24 | d | deci | -1 | 
| Z | zeta | 21 | c | cent | -2 | 
| E | exa | 18 | m | mili | -3 | 
| P | peta | 15 | mu | micro | -6 | 
| T | tera | 12 | n | nano | -9 | 
| G | giga | 9 | p | pico | -12 | 
| M | mega | 6 | f | femto | -15 | 
| k or K | kilo | 3 | a | atto | -18 | 
| h or H | hecto | 2 | z | zepto | -21 | 
| D | deca | 1 | y | yocto | -24 | 
Remark
You cannot use a prefix with a built-in unit if the result gives another 
built-in unit.
For example, 
1_a is one are, but 1_Pa is one pascal and not 
10^15_a.
 
 
