Hi Robin
it changes the addressing from relative to absolute
e.g. if i have in cell C1 the formula
=A1*B1
and i fill it down to C2 the formula will change to
=A2*B2
or if i fill it across to D1 the formula will change to
=B1*C1
- this is relative addressing and is the default in excel
however sometimes you want to "fix" the cell reference in a formula and this
is where the $ come in
=A1*$B$1
filled down from C1 to C2 will change to
=A2*$B$1
filled across from C1 to D1will change to
=B1*$B$1
however, sometimes i might want the row to stay constant (absolute) and the
column change so i would use
=B$1
othertimes i might want the column to be absolute and the row relative
=$B1
you could also check out the following article
http://www.cpearson.com/excel/relative.htm
Hope this helps
Cheers
JulieD