Ever had to add up the columns in a table with mixed KB, MB and GB quantities like this:
| In | Out | Total |
| 0.10KB | 0.34KB | 0.45KB |
| 0.33MB | 0.40MB | 0.73MB |
| 0.33KB | 0.41KB | 0.74KB |
| 0.69GB | 0.12GB | 0.82GB |
Using OpenOffice 2.4 or later you can use regular expressions and backreferences to convert the data in a table like this to a common unit and add them up. Click on "Find and Replace" and enter the following into the Search for field:
([0-9]+)\.([0-9]+).?MB.*
And in the Replace with field:
=SUM($1$2$30*1.024)
This will match a field like 1.32 MB and replace it with a KB value: 1351.68 You can do the same with GB values by replacing "MB" in the Search string with GB and also changing 1.024 to 1024. To get rid of the KB strings you can simply search for KB and replace it with an empty string. Now your table will consist only of numbers which you can conveniently add.