Sum will not show value result

I am trying to add a column of figures. I use the Sum function and the function appears in the cell box at the top but nothing appears in the cell on the spreadsheet. Tools|Options|LibreOffice Calc|View has formulas unchecked. If I check it I get the formula but if I uncheck it I get nothing, makes no sense. Any help appreciated.

Please check that the content of the cells are not as text (right-click and “format cells”)

Problem resolved. I found after I closed the spreadsheet and reopened it the values appeared. May have been that the tools options settings did not apply themselves to the spreadsheet until after it had been shut down.