Hi Anne, change this line...
Set Rng = Range("A1:A6")
to this to join all the cells into one big range...

Set Rng = Union(Range("Rng3"),Range("Rng4"),Range("Rng5"),Range("Rng6"))
The code you posted will work, but it just means its clearing the merged cells several times (once for each cell in the merged area). Not a biggie on a small range but may be slightly slower for a larger range.