Related Clues:

• Calculate sums
• Do some simple calculating
• Latin 22-Across
• Latin 51-Across
• Do a summer's work?
• Compute, sometimes
• Write, as a P.S.
• Offer as a bonus
• 'Cogito, ergo --'
• Dim follower
• Make a contribution
• Write in a postscript, e.g.
• Use a '+'
• Substance companion
• Calculate the total