Question
starting a cuttlng of a silver dollar or pear catus

Answer
Doug,

By silver dollar cactus I presume you are referring to a Astrophytum asterias. I don't believe that cuttings can be made with that plant. For a prickly pear, simple remove one of the pads. Let it dry out for a week or two, then plant it in some soil. They are very easy to grow and should root in about a month. Hope this helps.

Sincerely,

Greg