noun (n)

• the procedure of calculating; determining something by mathematical or logical methods(noun.act)

  Synonym:
  calculation, computing
  

  source: wordnet30
• problem solving that involves numbers or quantities(noun.cognition)

  Synonym:
  calculation, figuring, reckoning
  

  source: wordnet30
• The act or process of computing; calculation; reckoning.(noun)

  source: webster1913