Interpreting cell contents
Calc if a cell is defined as text, even if the cell contains a
number, then that cell is treated as text, which means it has the
numeric value zero for formulas.
example, if cell A1 is formatted as text and contains the character
“1”, in Excel a formula =A1+1 would return the value 2, but in
Calc it would return the value 1.
functions, such an entry will be ignored rather than treated
as zero. For example, the function AVERAGE will not treat a text
entry as zero, but will ignore it. If cell A1 is a text entry of “1”,
and cell A2 is a numerical entry of “10”, =AVERAGE(A1:A2) would
be 10, not 5.