=left(b1,16)
needs to match the number of rows in column B.

=isnumber(match(left(a1,16),c:c,0))
needs to match the number of rows in column A.

GARY wrote:

Hi Dave,

In c1, how far down does =left(b1,16) get dragged? (23,628 rows or
2,733 rows)
In d1, how far down does =isnumber(match(left(a1,16),c:c,0)) get
dragged? ( (23,628 rows or 2,733 rows)

--

Dave Peterson