Changing formula to add text

I'm using Excel 2010

I'm using the following formula which results in a %. For example, the result currently is "+3%". Instead, I'd like the answer to be "3 pts" but I'm not sure how to change the formula. Any help would be greatly appreciated

=IF(ISERROR(+W7-Y7),"",(+W7-Y7))

so that formula returns 0.03 cell formatted as %? if so change to

=IF(ISERROR(W7-Y7),"",(W7-Y7)*100&" pts")
or custom format #" pts"
and use
=IF(ISERROR(W7-Y7),"",(W7-Y7)*100)