Inspector wrote...
the name in B2 already exists in B2 on another sheet. I'm looking to
copy
the number to the left of that name in A2 on the other sheet to A2 of
this
sheet. I think the range should be $A$2:$B$288 so I tried this but it

doesn't work.
=IF(B2="","",VLOOKUP(B2,'Tally Sheet'!$A$2:$B$288,1,FALSE))
....

If you want to look up the B2 value in column B in Tally Sheet, you
can't use VLOOKUP on 'Tally Sheet'!$A$2:$B$288 because VLOOKUP will
search in column *A* for a match to B2. Looks like you need the
following instead.

=IF(B2="","",INDEX('Tally Sheet'!$A$2:$A$288,
MATCH(B2,'Tally Sheet'!$B$2:$B$288,0)))