when pasting text into the open office / libre office spread sheet application, the pasted numbers are recognised as text. to convert them,
- select cells
- right click — format cells — number
- menu “edit”: find and replace — from .* to & — check regular expressions
found on http://mynthon.net/howto/-/OpenOffice%20-%20Calc%20-%20convert%20text%20to%20number.txt