hi
they look like sheet names. i read the formula like this
Adds!$D$1:$D$51 - sheet name and range to evaluate
Detail!$B276 - sheet name and range for criteria
note: not sure what the "="& is about
Adds!$F$1:$F$51 -sheet name and range to sum.

i think the formula is on a third sheet, not on sheets adds or sheet details
because if the formula was on sheet adds, it would look more like...
=SUMIF(D1:D5,detail!B2,F1:F5)

does this formula work?
anyway that is what it looks like to me.

regards
FSt1

"cinvic" wrote:

I am trying to understand the syntax in this formula. What does "="&Detail!
as to do?

=SUMIF(Adds!$D$1:$D$51,"="&Detail!$B276,Adds!$F$1: $F$51)