what does error code 510 mean when using formula using calc

I am trying to total certain cells together in a row and when I type in the formula in the cell I want my answer it tells me ERR:510 where do I find what that means. I have checked my formula and all cells seem to be entered correctly. hope someone can help me… I am new to Libre office,and this forum, but unable to find error codes anywhere.
Thank you in advance

FYI - Error Codes in LibreOffice Calc. A bit outdated but something.

Err:510 means Variable missing (you also see that in the status bar when the cell cursor is on the formula cell that produces the error). Usually this means that a function used in the formula expression expects more parameters than provided.

You didn’t specify the expression that produces the error, so…

Thanks so much, After your response I went over everything again, and found I used number 0 vice letter O.
Thanks