Try one of these:

The 2-part method
=SUMIF(Reasons,"b scale",M20:M33)+SUMIF(Reasons,"b scale night",M20:M33)

The combined 2-part method
=SUM(SUMIF(Reasons,{"b scale","b scale night"},M20:M33))

If you need to sum any cell beginning with "b scale"
=SUMIF(Reasons,"b scale*",M20:M33)

Does that help?
(Post back if you have more questions)
***********
Regards,
Ron

XL2003, WinXP


"Barb" wrote:

=SUMIF(Reason,(OR("B Scale",B Scale Night)),M20:M33)

I am trying to sum cells in column M20:M33 if the named cells "Reason"
contain the words "B Scale" or "B Scale Night"

What am I doing wrong?