Related Clues:

• Calculate sums
• Do some simple calculating
• Do a summer's work?
• Compute, sometimes
• Write, as a P.S.
• Offer as a bonus
• Make a contribution
• Write in a postscript, e.g.
• Use a '+'
• Calculate the total
• Cookbook directive
• ___ insult to injury
• Contribute, as to the conversation
• Do sum work
• Include, as a tip