Related Clues:

• Viper with a different tail, it is calculated
• Part of VAT
• Tallied one's score
• Produced a sum
• Totalled
• Extra trod warily, having lost page
• Did sum work?
• Acquired some more
• Supplemental
• Totted
• Dead complicated, 500 plus 6
• Did a little math
• Used a calculator
• Piled on
• Used the + key