"Entering numbers as text
A number can be entered as text.......[by prefixing an apostrophe]
The data is now regarded as text by Calc.....
Typically, formulas will treat the entry as zero and functions will ignore
it."
How I wish that this was true, but it is not.
Formulas will treat an entry of the form '12345 as the number 12345, not
text, and include 12345 in the formula evaluation.
Functions will ignore the '12345 entry, as stated.
"Real" text in a cell is not, unfortunately, treated as zero by formulas.
Such "real" text is also ignored by functions, but formulas encountering
actual text crash, returning #VALUE!.
I include a 5x10 sheet to illustrate the points:
LO-Calc-Text-Error-Demo.ods
<http://nabble.documentfoundation.org/file/n4034468/LO-Calc-Text-Error-Demo.ods>
By design, the apostrophe does not display in cell A2, but it is there as
can be seen.
The above assertions pertain to Calc 3.5 on Win7.
This may not be the place for a question, but I would welcome any
philosophical musings as to WHY, other than aping Excel, text should be
treated so dramatically differently in formulas vis a vis functions. Lotus
123 behaved properly in this regard; why did its follow-ons go so wrong?