Cell F13s formula is: =SUM(ROUNDUP(B6/F9,0))
Cell B6 and Cell F9 are cells that I have to provide information in if they
are applicable. Sometimes these cells do not require information to be
filled in, which results in Cell F13 to read, #VALUE.

I would like Cell F13 to have 0 or N/A when there is no need for information
in Cells B6 & F9. However, I do want Cell F13 to produce a number when
numbers are provided in Cells B6 & F9.

Can anyone provide me with the formula to achieve the above?