Quick fix

[tamiwami]

New to excel, have a formula that doesnt seem to work. Anyone know how to fix?

=SUM('Jan 14'!L24+'Jan 28'!L24+'Feb 11'!L24+'Feb 25'!L24+'March 11'!L24+'March 25'!L24+'April 8'!L24+'April 22'!L24+'May 6'!L24+'May 20'!L24+'June 3'!L24+'June 17'!L24+'July 1'!L24+'July 15'!L24+'July 29'!L24+'Aug 12'!L24+'Aug 26'!L24+'Sept 09'!L24+'Sept 23'!L24+'Oct 07'!L24+'Oct 21'!L24+'Nov 4'!L24+'Nov 18'!L24+'Dec 2'!L24+'Dec 16'!L24+'Dec 30'!L24)-L25

 

[Joe4]

Since you are manually putting a + between each range reference, why are you also using SUM?
SUM and + do the same thing, so you only use one or the other, not both.
SUM is more typically use to sum a range of continuous cells, i.e.
=SUM(A1:A10)

I would recommend starting with your first addition, like this:
='Jan 14'!L24+'Jan 28'!L24
if that works, add the next value.
Continue adding them, one at a time, until you run into your problem. Then you know that the last one you tried adding is your problem.