Cell to be blank if reference cell is blank or show value if value is there even when value is zero

[HopefulGJL]

Hello,

I have a multiple tab spreadsheet.

The following formula works perfectly with one exception:
=Sheet1!C11+Sheet2!C11+Sheet3!C11

The issue (exception) is that it returns a zero even when C11 on Sheet 1 is blank. If C11 on Sheet 1 is blank, then I need the above formula (or some variation thereof) to be blank.

If C11's value is zero (0), then I need the above formula (or some variation thereof) to reflect 0 (zero).

If C11's value is say 5, then I need the above formula (or some variation thereof) to reflect 5.

I have been searching for the answer online and have tried multiple combinations and still have not found the answer. I really appreciate any assistance you can offer in advance.

 

[HopefulGJL]

Thank you so much for all of the assistance, and I'll consider this resolved; it is excellent to have the answers!