How to find the number how often a string appears in an odt or ods?

Would be great to know …

With Writer just see values in the Status bar after “Find All”

With Calc result of the search isn’t “words”, it is a count of cells. But you can copy a content of spreadsheet to new ODT as Unformatted text and repeat this trick

In Calc:

To see the Search Results dialog Summary on search must be enabled (choose Tools - Options - LibreOffice Calc - View).

You could also enable CountA in the Status Bar.

With LibreOffice (x86); OS: Windows 6.1.